Others like FZL and ELIP2 are known to be involved with chloroplast development

In order to avoid this issue, the present study examined the effects of fruit load in A. thaliana. Although an annual species, this plant produces many more fruits than alternate bearing trees, and has the potential to exacerbate the fruit load experienced by the inflorescence meristem. To identify how the fruit load changes expression patterns, surgically dissected IM apices were collected after producing more than 30 fruits, and were profiled with ATH1 microarrays. This analysis found relatively few differentially expressed genes, though the overall pattern was consistent with carbohydrate starvation and clearly supports the competition model. No evidence of flower inhibition was found, and instead flower promoting genes were strongly up regulated, which is inconsistent with the inhibitor hypothesis. The fruit dominance model was only weakly supported by the present data, though this may be related to an atypical dominance mechanism in A.thaliana. Further analysis of IM growth patterns supported the existence of a determinate growth pattern,growing raspberries in pots which displayed both fruit load dependent and independent effects. The arrest of IM activity was correlated to rosette leaf senescence, and eventually terminated through a localized senescence mechanism.

In order to observe how fruit load affects meristem activity, a microarray experiment was performed to correlate gene expression patterns with the three alternate bearing hypothesis. However, because microarrays only measure the relative concentration s between different transcripts, this procedure cannot directly identify the cause of the observed levels. The input from mRNA biosynthesis is differentially regulated than the catabolism processes that reduce the overall transcript pool, and both forms of regulation are in turn affected by changes in any of the multitude proteins that control them. In order to obtain this regulatory information, it would normally be appropriate to perform additional microarray experiments in the presence of chemical inhibitors to block key enzymatic steps, and to validate the actual expression levels in a subset of genes with RT-PCR or qPCR methods. Unfortunately, due to the circumstances of Dr. Smith’s departure, none of this work was performed as expected. Consequently, the data presented below is best interpreted as a preliminary analysis, providing a number of hypothesis that might be investigated in future studies. To begin, meristem tissues were surgically dissected from A. thaliana 1° inflorescences using plants grown in both long day conditions , and from plants grown in continuous light . Total RNA was extracted from each replicate, and then hybridized to five individual Affymetrix GeneChip ATH1 microarrays . An initial analysis revealed less than 100 differences between the two photoperiod treatments, and no clear patterns were found in any cellular functions, gene families, or metabolic pathways. In the absence of any significant differences between the two photoperiods, the data sets were combined, providing a total of five biological replicates for the high fruit load treatment.

Unfortunately, due to the abrupt end of my work in this lab, control tissues from de-fruited plants could not be collected as expected. Instead, a previously published microarray data set was chosen to replace the missing controls, providing 3 biological replicates. From the combined 5 x 3 array analysis, 15,473 genes were detected at least once, and 7337 were detected in all eight arrays. This list was further filtered to remove genes that had Bayesian probability scores below 1.5, and filtered to remove genes than had an adjusted p-values greater than 0.05. To focus on those that were most significantly affected by fruit load, only genes with logFC values above +2 or below-2 were selected for further analysis, providing a list of just 512 genes. Initial examination of functional annotations however, revealed a large number of genes known to be exclusively expressed in the pollen, most of which had elevated transcript levels in the high fruit load treatment. Curiously, this pollen signal was shared with a previous meristem profiling experiment, where it seemed equally anomalous This prompted a re-evaluation of the tissue collection procedure used in the present study, which revealed a highly probable route of pollen contamination that had previously been overlooked. This finding strongly suggests that the pollen-specific genes detected in both studies are false positives. To remove this source of bias, the expression pattern of all 512 genes was scored using the eFP browser. This found 66 genes that were exclusively expressed in the pollen, and another 33 that were specific to green embryos, and are also likely products of contamination. In contrast, 17 genes were expressed largely in immature flower buds, but unlike the pollen signal, these were often had severely reduced transcript levels. Instead of contamination, the reduction of flower bud specific transcripts most likely reflects a tissue collection bias The tissue for the control arrays removed flower buds around the SAM older than stage 6, while the present study removed flower buds older than about stage 3 . All 117 atypical genes were subtracted from the total, leaving a final list of 389 differentially expressed genes . Of these genes, 103 had reduced transcript levels, and 286 had increased transcript levels. Mapping of functional annotations within this data set revealed no clear trends, but instead found a widespread pattern where most functional pathways were represented by at least one or two genes.

Although coverage is sparse, in many cases it was possible to estimate the direction of metabolic flux and the larger impacts on cell physiology. When compared to SAM tissue collected under low fruit load conditions, the high fruit load treatment correlated with reduced transcript levels for several cell wall components, including the glycoproteins PRP2, PRP4, and the putative leucine-rich protein At4g18670. The existing glycoproteins may also be degraded, as the xyloglucan hydrolase TCH4 transcripts were elevated. These observations also parallel the findings for lipids, where several biosynthetic genes had reduced transcript levels , whereas one lipid catabolism gene showed an increased transcript level . The reduction of two potassium channel transcripts, KUP7 and KEA2, might also suggest that the plasma membrane and chloroplast envelope have a reduced capacity to maintain normal charge separation.For the high fruit load treatment the meristem tissue was collected near the time of apical arrest, after which the meristem tissues often became visibly dehydrated. To see if the early symptoms of dehydration were already present when the tissue was collected, the data was compared to young meristems in the absence of fruit load. This revealed a reduction in the transcripts of CER1, a gene involved in wax biosynthesis,plastic plant pot suggesting a loss of the waxy cuticle. Desiccation stress responses are indicated by the elevated transcript level of the abscisic acid biosynthesis gene NCED3. Several other abscisic acid responsive genes had elevated transcripts, including HVA22J, TSPO, HB5, and so did genes known to be up regulated by drought stress, such as HIS1-3, ERD14, and RD20. Most intriguingly, the high transcript levels of METACASPASE3suggests the existence of a programmed cell death response in the apical tissues. Although the exact role of MC3 is not well understood in plants, in animal models PCD is typically activated following the rupture of the mitochondria, flooding the cytoplasm with free radicals that then triggers a proteolytic cascade regulated by CASPASE enzymes. Depending on the tissue type and the nature of the stimulus, the destruction of the cell can follow one of three recognized patterns: necrosis, where the cell is rapidly destroyed by physical damage to its membranes, apotosis, where the cell breaks apart into small fragments that are eventually cleaned up by macrophages in the bloodstream, and autolysis, were significant portions of the cytoplasm and nuclei are enclosed in lytic vesicles and digested. Apotosis is further correlated with DNA laddering produced by the fragmentation of nucleosomes, while necrosis and autolysis tend to produce high molecular weight smears. In plant tissues, the mitochondria have been found to play a similar role in autolysis pathways, and this is supported by the present study, which found that two carbonic anhydrase transcripts, BCA3 and BCA6, were elevated under high fruit load treatment. The proteins produced by these two genes are localized to thechloroplasts and mitochondria, and this pattern suggests an increase in the concentration of dissolved bicarbonate ion. However, no other freeradical responses were detected in the current data, so the significance of this observation is unclear. In order to discriminate between the three modes of cell death, multiple attempts to observe the characteristic DNA laddering of apotosis were performed. Surprisingly, this found traces of DNA laddering in actively growing meristems, but not in older quiescent meristems, which instead produced high molecular weight smears . The necrotic mechanism might be indicated by the previous predictions for a weak cell wall, and by the presence of senescent pathways, though it is unlikely in the absence of any obvious sources of physical damage. Autophagy in contrast, is supported by the high transcript levels of AUTOPHAGY 8H , which may also have a role in ubiquitin-related protein degradation.

Under high fruit load conditions three catabolism genes were found to have higher transcript levels, which suggests that nitrogen is released as a part of protein catabolism. One is At4g33150, which is involved in lysine and ɑ-ketoglutarate hydrolysis, and the other is At5g18860, involved in nucleoside hydrolysis. The third gene, the methionine gamma-lyase At1g64660, more specifically suggests that nitrogen is released as ammonia. This is at odds however, with the increased transcript levels of the glutamine synthetase GLN1-4 and the nitrate importer NRT1.2, both of which suggest nitrogen shortages. The elevated transcripts of AGL44 is more difficult to interpret, because although AGL44 is annotated as a nitrate responsive gene, this gene does not always respond to nitrogen starvation.Compared to the absence of fruit load, meristems treated with high fruit load appear to convert their starch reserves into sucrose and exported the sugar out of the SAM. This is supported by the increased transcript levels of two putative Trehalose 6-Phosphate Phosphase genes which suggests that less starch biosynthesis occurs, and this correlates well to the increased transcript levels of the starch degrading enzyme AMY1. Although there are no detected genes for glycolysis or the TCA cycle, the simultaneous increased transcription of the sugar importers SUC2and ATPLT5suggests that the meristem cells are experiencing a carbohydrate shortage. Calcium signaling pathways are over-represented in the data set, comprising 48% of all detected signaling components, most of which show increased transcript levels under high fruit load conditions. Those with annotated functions suggest a role in wound, phosphate starvation and/or desiccation responses. These functions are also shared with the WNK4 kinase, which strongly implies that these signaling components have role in the senescent pathways described above.Mutants of FZL are known to produce irregular grana structure, while the over expression of ELIP2 reduces chlorophyll content. These findings mirror the reduction of FZL transcripts and the increase of ELIP2 transcripts detected in the present study, and suggests that chloroplast function has been compromised. Most chromatin binding proteins had reduced transcript levels under high fruit load, such as FAS1, ATX1, DMT7, and BRAHMA. Mutants in FAS1 are known to reduce heterochromatin, so the reduction of FAS1 here might lead to an increase of euchromatin. This is also supported by the reduced transcript levels of the histone methyltransferase ATX1and the DNA methyltransferases , which would likely increase the amount of euchromatin simply by shifting the balance toward acetylated histones, and by making it harder to maintain silenced DNA though cell division. However the reduction of the chromatin remodeling factor BRAHMA suggests that transcription rates in general might be reduced, despite the possible increase in exposed DNA. There is also evidence of DNA damage, as two nucleases had elevated transcript levels, while a loss of double-strand break repair is suggested by the reduction of HDG12 transcripts. Preliminary analysis of the microarray data indicated a strong senescent response, which was unexpected given that several steps had been taken in order to avoid senescent tissue. Reasoning that the tissue collection procedure had relied on an inadequate predictor of senescence, an attempt was made to identify better markers for future use. This was done by measuring leaf and bud growth rates every two days over entire lifespan of the plant, then searching for strong correlations that occurred at least 3-4 days before the symptoms of senescence became visible. Under the long day conditions, Col-0 plants were found to have a population of immature flower buds that varied over time, reaching a maximum at the first flower and then declining briefly before leveling off at about 10 buds .

Each well carries out an independent PCR reaction simultaneously

Injections of antibiotics have been the primary focus and several issues have hampered commercial development: cost of treatment, damage inflicted on the tree as a result of multiple injections, phytotoxicity of antibiotic treatment, and concerns over bactericide residue in the fruit. Cost can be high because of the labor intensive process of injecting each tree and/or the cost of the injection apparatus. Since the bacterium resides within the phloem cells, effective control requires the bactericides to first enter the tree and then move systemically throughout the vascular tissues. Damage from the injection process can create scar tissue that impedes normal transport of nutrients throughout the tree, and phytotoxicity is exacerbated because treatments require a high dose of the bactericide applied to a small application site. Our research was conducted to determine if effective treatment application strategies can be developed that reduce phytotoxicity and plant damage and also reduce the long-term cost by reducing labor costs of using bactericides in an HLB IPM strategy. We have shown that three bactericides—oxytetracycline, penicillin,maceta de plastico cuadrada and streptomycin—can be applied in ways that cause the molecules to penetrate plant tissues and move systemically throughout the plant. We have also developed a strategy for therapeutic delivery of the antibiotic in a “time-release” strategy that should reduce the phytotoxicity and cost of multiple applications.

Encouraging results on greenhouse and research plots have led to current commercial grove application trials testing different application strategies and comparing effectiveness. Huanglongbing is caused by a phloem-limited bacterium, Ca. Liberibacter asiaticus in the United States. The bacterium often is present at a low concentration and unevenly distributed in the early stage of infection, making reliable and early diagnosis a serious challenge. Conventional diagnostic techniques, including real-time PCR , have often failed at early detection of HLB. We have demonstrated a promising novel diagnostic assay based on digital PCR for early and reliable detection of HLB. dPCR has revolutionized the detection of rare pathogens and nucleic acid molecules as it partitions samples into tens of thousands of picoliter wells in a single reaction.The number of negative and positive wells can then be fitted into a Poisson distribution to allow absolute and precise quantification of the target molecules in a sample without the use of a standard curve. The large number of independent reactions in a single assay makes it possible to apply statistical tools to estimate a level of precision and confidence interval of the measurement. Using probes targeting the Las 16s rDNA and the integrated prophage repeat sequences, we show that as few as 1–2 copies of the targeted DNA molecules per microliter can be detected, with the prophage probe providing the best sensitivity. The copy number measurement of the targeted DNA molecules can be statistically differentiated from the healthy sample and negative water controls. Furthermore, this assay can quantitate the copy number of the 16S rDNA and the phage repeat DNA simultaneously, permitting the tracking of lysogenic and lytic activities of the Las prophage/phage accurately.

The dPCR‐based assay will not only provide a reliable and early diagnostic tool but also an enabling technology to advance research on HLB therapies. Accurate and timely detection is critical for the eradication of Huanglongbing . Unfortunately, early HLB detection is challenging because infected citrus plants remain asymptomatic, sometimes for years; furthermore, the HLB-associated bacterial pathogen Candidatus Liberibacter spp. exhibits uneven distributions in infected trees with low titers. Very often, CLas cannot be detected by quantitative PCR even in symptomatic branches or leaves. To date, reliable methods for HLB early detection and the ability to process a large amount of samples necessary to track HLB epidemic are urgently needed. In the past several years, we have identified unique secreted proteins of CLas as markers for HLB detection and developed an antibody-based detection method using a simple branch imprint assay. The basic idea is that although CLas has sporadic distribution in the phloem of infected trees, proteins secreted from CLas cells into the phloem can be systematically distributed in the infected trees through the vascular flow. As such, serological detection methods based on CLas-specific secreted proteins will better cope with the large variability in the distribution of CLas cells within infected trees and the various degrees of disease progression, and thereby increasing the chances of HLB detection in a direct and highly specific manner. Our preliminary research suggest that this method holds promise for allowing early detection of newly infected trees and large-scale field surveys. Since its earliest known occurrence in California, the Asian Citrus Psyllid has spread rapidly across the urban landscape of southern California. It is not surprising that much of the observed ACP infestation occurs within the urban areas of Los Angeles. However, to-date little is known about the factors that influence the spread and distribution of ACP at the landscape level.

Our study focuses on understanding the colonization and distribution pattern of ACP across a predominantly urban landscape by using a combination of GIS tools and spatial models. More specifically, we first explore the role of roads in the colonization of ACP during early stages of spread and then develop several regression models to identify the key exogenous and endogenous factors that influence the eventual landscape-level distribution of ACP. Analyses of road-proximity patterns among ACP occurrences captured at different temporal stages of spread for each county showed that the initial occurrences of ACP were strongly and positively influenced by the network of roads for the counties of Los Angeles and San Diego. Logistic regression model highlighted the strong influence of ‘percent impervious surface’ and ‘NDVI’ as the key landscape factors along with ‘rain in warm quarter’ as the most influential bio-climatic factor in determining the occurrence of ACP in the urban landscape. Inclusion of spatial and temporal patterns of ACP occurrence as an auto-covariate further improved the fit of regression models, suggesting the role of fine scale endogenous process like dispersal in determining ACP occurrence. Results from the best-fitting spatiotemporal auto-logistic regression model shall eventually be used to develop habitat suitability map for ACP. Before HLB, the useful lives of the plants were larger than 20 years. Now it was estimated, even with modern managements, an average is 14 years. When plants are managed with HLB, eradicating the plant stand decreases, making low productivity and impeding the maintenance of the area, and making it necessary to eradicate all plants and plant new plants. A good strategy to have new citrus area is to induce vigor to have high productivity rates and earliness, getting “payback” in the first years. Some insecticides, like the neonicotinoids group, have demonstrated physiological action on treated plants – like increased vigor, shoot and root development, better absorption of nutrients and water, increased enzyme activity, resistance, and productivity. To evaluate vigor, healthy nursery trees and standardized Valencia orange single stem produced in greenhouse were planted in pots in randomized blocks and treated with systemic insecticides action indicated to manage the psyllid. The experiment was conducted with six treatments—three different doses of thiamethoxam, one of Imidacloprid, Aldicarb,maceteros reciclados de plastico and Check without insecticide. We evaluated the development of plants every 15 days until 150 days after planting, evidencing that all the treatments had an increase in trunk diameter, with the thiamethoxam treatments differing significantly from Control. Thiamethoxam at a dose of 1 g per plant produced fresh and dry weight of root differing from Check. This treatment also had higher weight of shoots. That way, treatment with thiamethoxam at a dose of 1 g per plant had the best results in all studied characteristics providing better vigor and plant development during the study period. Considerable research has been conducted toward developing and implementing HLB and ACP management strategies. With respect to ACP control, of interest is that reports indicate guava, Psidium guajava, can be repellent to ACP. We conducted research to further assess repellency of guava to ACP. In one set of experiments, guava oil from five Brazilian cultivars was extracted from leaves by hydrodistillation in a Clevenger apparatus and evaluated for psyllid repellency. In a second set of experiments, repellency of guava leaves to ACP was investigated using leaves from two guava cultivars, ‘Pink’ and ‘Thai White’. Repellency was evaluated by releasing ACP adults into a cage with two vials, one containing a young flush of Murraya exoticaand one with M. exotica flush and the test material of interest . The adults were free to move throughout the cage and into the vials. After 24 hours, the number of psyllids in each vial was counted.

The results obtained showed that all guava materials tested had at least some repellency to ACP. Mature guava leaves had a greater repellent effect than young flush. Each of the five oils exhibited repellency. There were no differences between males and females with respect to guava repellency. A report in the literature suggested that sulfur compounds associated with guava may be responsible for ACP repellency. Interestingly, the five guava oils we studied were repellent to ACP, but three did not appear to contain any sulfur compounds. Identification of the constituents responsible could lead to new management tactics. Orchard renewal is a special challenge where HLB is endemic. Young trees are especially susceptible to the disease and continuously attractive to the psyllid vector due to frequent flushing. Therefore, heavy reliance is placed on soil‐applied systemic insecticides to protect young trees. We conducted a one year study to evaluate foliar concentrations of neonicotinoids and cyantraniliprole applications and two multi‐year studies to assess long‐term ACP control and consequent protection from HLB. In the first study, we found detectable levels of cyantraniliprole and significant reduction of ACP nymphs 295 days after a drench application to 2‐month-old trees. In the first long‐term trial, ACP adults averaged 1.4 per tap under heavy pressure on untreated trees over 2.5 years, compared to 0.06–0.11 on trees treated at 3‐month intervals with rotations of neonicotionoid and cyantraniliprole drenches. Incidence of HLB reached 49% on untreated trees after 2 years compared to 6.3% on treated trees which later rose to 98% after 3.5 years. Trunk diameter on treated trees after 3.7 years was 37% larger and yield 6.5 times greater compared to untreated trees. During 15 months after planting the second long‐term trial, shoot infestation averaged 60% and adults 0.9 per tap compared to 7.1% and 0.04 per tap for trees treated with a neonicotinoid – cyantraniliprole rotation. The numbers for repeated imidacloprid application were 12.7% and 0.08 per tap and repeated cyantraniliprole 18.0% and 0.08 per tap. HLB incidence was already 46% in the check compared to 12.5% for the rotation and 29 and 25% for imidacloprid and cyantraniliprole, respectively. Drip injection worked better than drench, once roots had established around emitters spaced at 30 cm. Huanglongbing , the most devastating citrus disease worldwide, is threatening the citrus industry in several countries, mainly Brazil and United States. HLB is a bacterial-caused disease transmitted by the Asian Citrus psyllid . Currently there is no cure for this disease and no identified genetic resistance in the genus Citrus. An emerging technology, RNA interference , which is a natural biological process that selectively down regulates the expression of a specific gene, is being developed as a more environmentally friendly approach to control insects. The feasibility of RNA interference strategies supports a method that would be highly specific ACP populations. One question that needed to be addressed was the effect, if any, on ACP response to plants treated with an RNAi product. To evaluate if ACP sensed the presence of an ACP-specific dsRNA in plants, the experiment examined psyllid response to dsRNA treated plants versus non-treated plants. Four groups of six plant flush each were placed in each corner of a cage, and 100 ACP were released at the center. They were observed for 15 days, and the number of ACP on each flush recorded daily. A significant difference, using t-test analyses, showed more psyllids on the dsRNA treated plants than on untreated controls . Psyllids appear not to be sensitive to dsRNA ingestion, as they may be for traditional chemical insecticides, thus were not repelled. These preliminary results suggest that RNAi-based products may actually increase psyllid feeding from the treated trees, thus increasing RNAi efficacy, by increasing the amount of dsRNA each psyllid would ingest.The Asian citrus psyllid, Diaphorina citri, is an oligophagous herbivore that transmits Candidatus Liberibacter asiaticus, the devastating pathogen causing citrus greening disease.

Real promotion expenditures represent the key variable of interest in all 4 models

To test the robustness of our findings, we perform several checks. First, we test the sensitivity of the baseline results to various assumptions about the seasonality parameters. We use only data for one year before the recall instead of using, as above, all previous years . This yields very similar drops in purchases as when we include all previous years. Second, we test the sensitivity of the baseline results to using Washington as a control state by excluding data from Washington and using stores in Southern California as controls. The rationale is that we may assume that stores in Southern California have similar trends to stores in Northern California. Once again, using Southern California stores as counterfactuals for Northern California store patterns yields very similar estimates of the egg recalls. Third, we test the sensitivity of the baseline results to using only one month after the event week. We obtain data on a second post-event month and include a total of eight weeks after the event week for all years. While this additional robustness check gives us similar results to the ones from the main specification, we find that the effect lasted more than one month.Since HAB assessments to support avocado promotion began in 2003,arandano azul cultivo avocado imports and total U.S. supplies have continued to increase to a record total of over 1.6 billion pounds in 2012.

Mexican avocado exports to the U.S. increased significantly after Mexico gained year-round access to all states except California and Florida in 2005 and to all states in 2007. Mexican imports of 933.8 million pounds accounted for over 58% of the total U.S. supply of fresh avocados and for 86.7% of total fresh avocado imports in 2012. Market share for imports increased from 30% in 2000 to 67% in 2012. The U.S. demand for avocados has grown substantially in the ten years since the HAB began funding promotional programs in January 2003. As shown in Figure 1, U.S. consumption has exceeded two pounds per capita annually since 2001, exceeding three pounds per capita in 2005, four pounds per capita in 2010, and five pounds per capita in 2012. Figure 1 also depicts the average price per pound in real terms received by California growers for these same years. The farm-level demand for avocados is widely acknowledged to be quite price inelastic, with empirical estimates typically near -0.25. In the absence of substantial demand growth, one would have, thus, expected sharply lower prices to accompany an increase in avocado supply of over 200%. But, despite the real grower price exhibiting considerable year-to-year volatility it has, on average, remained stable over this time period, reflecting the substantial demand growth that has occurred.Initiation of assessments on all Hass avocados sold in the U.S. market in 2003 and increasing Hass avocado imports has significantly increased the availability of funds for promotion programs. Table 1 shows promotional expenditures by year for avocados from the U.S. , Chile , Mexico , and Peru , plus promotional expenditures made by the HAB itself.

During the HAB’s first five years of operation, 2003 through 2007, CAIA, MHAIA and HAB spent $40.32 million promoting avocados in addition to $50.98 million spent by California producers. Total CAC promotional expenditures for the next five years, 2008–2012, decreased just over 10% as a result of relatively small crops in 2009 and 2011. But promotional expenditures by HAB and country organizations financed by fresh avocado imports raised average avocado promotion from $18.26 million annually from 2003 to 2007 to $29.95 million annually from 2008 to 2012 .Carman, Li, and Sexton conducted the first evaluation of the HAB promotion programs for the five-year period from 2003 through 2007. CLS found that advertising and promotion funded under the HAB increased the demand for fresh avocados during the program’s first five years of operation and yielded a favorable rate of return to avocado producers. Annual Demand for Avocados Economic theory posits that demand for a commodity is a function of that commodity’s price, prices of goods that are used as substitutes or complements for the commodity, and consumer income. Successful promotions can also be an important factor in expanding demand for a product. We estimated annual per capita fresh avocado demand as a function of price, per capita income, a time trend, and total HAB and CAC promotions. The annual model analysis utilized data from 1994–2012. Table 2 contains the annual demand model results for four model specifications. Model 1 in table 2 includes real f.o.b. price, real per capita income, and real promotion expenditures as explanatory variables. Model 2 adds a linear time trend, YEAR, to Model 1.

Models 3 and 4 are adjusted to account for the fact that price and consumption are likely jointly determined. These models use U.S., Chilean, and Mexican avocado acreage as instrumental variables for price.In all cases, promotion expenditures have a statistically significant and positive impact on per capita U.S. avocado consumption. The estimated coefficients for promotion expenditures range from 0.049 to 0.113 . Models 3 and 4, which have the best statistical properties among the models, yield intermediate values for the promotion coefficient of 0.052 and 0.077, depending upon whether per capita income is included in the model. Because the magnitude of the estimated coefficients depends upon the choice of units to measure the model variables, it is desirable to convert the coefficients to elasticities, which measure estimated percentage impacts and, thus, are unitless. The estimated promotion elasticities evaluated at the data means range from 0.153 to 0.354 . The other variables included in the model perform much as economic theory would predict and estimates are also consistent with prior work. The one exception is the impact of the income variable when it is included in a model with the time trend. These two variables are highly correlated and, in essence, it is impossible to isolate the unique impacts of growth in consumers’ incomes on avocado consumption from other economic factors that are captured in the trend term.The annual demand analysis presents strong evidence that generic promotion of fresh avocados has worked to increase the demand for fresh avocados in the United States. The additional question to ask, however,macetas 25 litros is whether the expenditures have “paid off” in the sense of yielding benefits to producers from the demand enhancement that exceed the money expended to fund the programs. The average benefit-cost ratio from a promotion program consists of the total incremental profit to producers generated by the program over a specified time period divided by the total incremental costs borne by producers to fund a program. The ABCR is the key measure of whether a program was successful, with ABCR > 1.0 defining a successful program. The marginal benefit-cost ratio measures the incremental profit to producers generated from a small expansion or contraction of a promotion program. MBCR answers the question of whether expansion of the promotion program would have increased producer profits, with MBCR > 1.0 indicating a program that could have been profitably expanded. Substantial diagnostic tests performed by CLS in their evaluation of avocado promotion supported use of a linear demand model, which we thus also utilized. For the linear model ABCR = MBCR, and the two questions “was the program profitable” and “could it have been profitably expanded” are one and the same. Our strategy in estimating ABCR and MBCR for the promotion programs conducted under HAB’s auspices was to simulate the impact of a small hypothetical increase in the HAB assessment rate from the current level of $0.025/lb. to $0.03/lb., i.e., an increase of one-half cent per pound, and estimate the benefits and costs to avocado growers from that assessment expansion based upon the results of the annual demand analysis. The simulation framework is depicted in figure 2.

The model begins with demand and supply functions for avocados that depict the U.S. market for a given year t. Thus, demand, Dt , is total U.S. demand in year t, on a per capita basis. Supply, St , is total supply to the U.S. market in year t from all sources. Under the current program, total U.S. consumption in year t, given functions St and Dt , is Qt , and grower price is Pt . Implementation of a one-half cent per pound expansion in the program assessment increases producer costs per pound by that half cent, S’ t as depicted in figure 2. The hypothetical increase in assessment generates incremental funds for promotions equal to the change in assessment multiplied by total shipments to the U.S. market. The marginal impact of the additional promotional expenditure on demand is determined by the regression coefficient for the promotion variable, which is reported for alternative model specifications in table 2. The new demand curve is illustrated in figure 2 by D’ t . The new market equilibrium is found at the intersection of curves S’ t and D’ t at point A in figure 2. Thus, the model predicts that equilibrium price in year t would have risen to P’ t and sales have risen to Q’ t with the incremental assessment. Producer benefits from the hypothetical expansion of the promotion program are measured in terms of the change in producer surplus . PS is the same as producer variable profits, namely revenue minus the variable production costs associated with producing and selling the output. We seek to measure the change in PS associated with the hypothetical expansion of the promotion program. In figure 2, PS after the program expansion is PS’ = P’ t x Q’ t – 0BQ’ t , but we must also account for the additional promotion expenditure, which is represented geometrically by the rectangle P’t P”t AB=Q’ t . Thus, the net increase in PS to producers from expansion of the promotion program is ΔPS = PS’ – Q’ t , which is represented by the shaded area in figure 2. Information required to estimate ΔPS consists of: an estimate of the marginal impact of promotional expenditures on demand, an estimate of the slope or price elasticity, ∈D, of the grower-level demand curve, and an estimate of the slope or price elasticity, ∈S , of grower supply of avocados to the U.S. market. The results of the econometric estimates reported in table 2 provide estimates of and . We evaluated these considerations, and specified three alternative values, 0.5, 1.0, and 2.0, as representing a plausible range of values for ∈S . Among the demand models included in table 2, we selected models 1 and 3 for use in the simulation. Benefits and costs were estimated for each of the five years, 2008–2012, under evaluation. The model was implemented by fitting the demand and supply functions to the actual values observed for the real grower price and per capita consumption for each year of the review period. St was then shifted vertically to S’ t by the half-cent incremental assessment for each year, and Dt was shifted horizontally to D’ t by the estimated promotion coefficient times the funds generated by the incremental assessment, producing the equilibrium at point A in figure 2 and enabling us to compute the hypothetical changes in P and Q and the ΔPS. Total net producer benefits are reported for each model by compounding the annual benefits and costs over the five-year period to 2012, using a 3% real rate of interest. The estimated benefit-cost ratios in this study range from 2.12 to 9.28. The lower bound is associated with model 3, which has a small coefficient for promotion relative to model 1, and the most elastic supply response, ∈S =2.0. The average annual increase in the grower price due to promotions for this simulation is 2.6%. The upper bound of 9.28 is associated with demand model 1, which has a high coefficient for promotion, and with the most inelastic supply response, ∈S =0.5. The average annual price increase for this simulation is 12.3%. Space considerations preclude us from discussing results of the disaggregate model estimated using scanner data. Those results are available upon request from the authors and showed a statistically significant positive impact of promotions on weekly sales in those market areas receiving promotions through the HAB, thus reinforcing the results from the annual model.

Access is provided through a common search portal and via RESTful web services

Root growth is extremely variable, presenting great sensitivity to the growth environment which could explain the non-significant differences in root growth over treatments and the differences between field and pot observations. Several studies described the impact of water deficit on root growth and the variability of root length for annual crops, such as wheat , cotton , sorghum and tree species . These results encourage the application of long-term experiments in order to clarify the link between root growth and canopy transpiration under water stress.Grapevine is a perennial plant that has been cultivated for more than 7000 years in many environments and according to many different viticultural practices. It is a globally important crop, eaten fresh or processed into various products including wine . Like other crops, it faces changing biotic and abiotic stresses linked to climate change or the introduction of exotic pests . The grape and wine industries, must in addition, cope with societal demands to reduce environmental impacts and improve product safety while maintaining cost-effective and sustainable production. Thus,macetas plastico cuadradas the major challenges for viticulture and enology are to control the final berry composition at vintage in variable environments and to sustain yield and quality while limiting the use of pesticides, water and other inputs.

In order to address the scientific questions related to these challenges, the grapevine research community is increasingly using high-throughput data-generative experimental techniques that generate large and heterogeneous data sets describing genotypes, phenotypes and the environment. Indeed, during the last 15 years, several high-throughput data sets from grapevine have been published, including Expressed Sequenced Tags , simple sequence repeats and single-nucleotide polymorphisms molecular markers , QTL maps and transcriptomes . The determination of the genome sequence of grapevine in 200713 created new possibilities for transcriptomic and proteomic studies and for better describing and understanding genome grapevine genetic diversity either through genotyping/re-sequencing studies or de novo sequencing of new genotypes.Phenotypes of different nature have been studied and here too, throughput has notably increased in recent years: for example, the study of single metabolites has been increasingly replaced by metabolomics studies and manual field or greenhouse scoring by the use of more automated processes . The greatest value of these data sets depends on their integration to generate new knowledge, and therefore on the ability to combine the results of different experiments. To allow this, data should be Findable, Accessible, Interoperable and Reusable . An emblematic model in the plant community is Arabidopsis thaliana, for which rich data sets are available and which has been used to derive working hypotheses for gene function in crop species. This has been supported by the TAIR portal and the more recent Arabidopsis Information Portal .

However, in grapevine, the increasing wealth of data is highly dispersed and often poorly accessible, hindering its effective exploitation beyond the scope of its initial production. Moreover, in the absence of dedicated funding and sufficient international collaboration, there is no information portal targeted at the grapevine research community. Although large international repositories do exist for molecular biological data , these do not systematically capture the detailed knowledge related to genome function , the plant material used and any non-molecular phenotyping data that is the specific expertise of grape researchers. Instead, these data are at best published along with research papers and managed in regional and local databases, or at worst isolated on individual researcher’s computers and completely inaccessible to the wider community. There is a clear need for research policies that create incentives favoring data sharing to improve the quality of research results and foster scientific progress.The interpretation of previously published data always requires additional ‘metadata’ to provide the appropriate context. In addition, both data and meta-data should also be formatted in standardized representations to enable its processing in an automated manner and avoid errors generated by manual manipulations, especially in the case of very large data sets.This requires community-wide agreement on guidelines for annotation, tools for data preparation, and the dedicated custodianship of important/exemplar data. Although generic solutions exist for many data types individually, much grapevine data is still far from FAIR, and little support is available for community members to make it so. In 2014, in response to the demands of the grapevine research community, the International Grapevine Genome Program consortium launched an action to define a strategy for the stewardship of grapevine genomic data to allow their easy access and reuse.

The first output was the proposition of a gene nomenclature;the second expected output is a strategy for the broader management of diverse grape data in accordance with the FAIR principles. In this paper, we outline such a strategy for the development of a global Grape Information System , a platform to enable access to a broad collection of data sets and reference data from a wide variety of sources with a flexibility that promotes the rapid introduction of new data sources derived from new and emerging technologies. To meet these objectives, we have devised a plan inspired in part by the experiences of the international Wheat IS initiative that provides a portal for wheat data and by the transPLANT infrastructure for plant genomic science that allows data integration from nine distinct European databases. The GrapeIS will comprise an open federation of independent information systems interconnected by a central web portal , and will provide a tool set to reduce the costs of data publication and interrogation. This will provide a robust, cost-effective model for data integration by exploiting the expertise of existing resources, and best practice and data standards from related research communities grappling with similar problems.Discovering data stored in distinct databases from a single entry point: interoperability of the infrastructures One model for providing integrated access to diverse data sources features a single data custodian, who takes comprehensive responsibility for the storage and integration of all relevant data. An alternative model is to provide an integrated query engine providing a common entry point to dispersed resources, each of which might contain different data . The second model has the advantage of exploiting existing resources . Such a common entry point should allow the discovery of different data types or data sets of the same type , facilitate their integration and facilitate the import of these data into diverse analysis or visualization tools. Achieving this requires a commitment from all contributing resources to serving data in accordance with a set of common standards, such that it can be automatically interrogated in a standard way. The first step in providing FAIR data is ‘findability’. A model for findability for plant-focused resources has been established by the transPLANT project. The transPLANT integrated search engine operates using the generic SolR search engine to provide search facilities over remote data files published by each participating resource conforming to a minimal standard schema .To support more advanced knowledge extraction, the automatic manipulation of data sets, and the efficient and correct reanalysis and re-use of data, a more advanced model is required.Data needs to be annotated with detailed and accurate metadata, requiring both manual curation and automated quality control . Where multiple resources are collaborating, agreement on a common set of controlled vocabularies is required; if vocabulary terms are structured as ontologies , the power of potential queries is increased. In developing such a model,maceta redonda the grape community will be able to draw on other ongoing efforts. Moreover, standard formats must be agreed for publishing such data; and appropriate forums identified for publicizing its availability. Standard formats already exist for many types of data: for example, General Feature Format and Genbank for genome and aligned data, Variant Call Format for nucleotide sequence variants, Binary Alignment Format for next-generation sequence alignments, BioPAX and Systems Biology Mark-up Language for pathways and networks, PSI-MI XML standard for proteomic data and a suite of standards are being proposed by the Data Standards and Metabolite Identification Task Groups of the international Metabolomics Society for metabolites analysis ,as in untargeted metabolomics, robust and standardized structural annotation of metabolites appears crucial to maximize their interpretation and impact. Moreover, international initiatives are on-going to agree on data models that specify APIs for different types of data in relation to plant breeding , genomics ,and with any other specific purpose . Other initiatives as for instance BioSharing , exist to publicize resources with a commitment to providing open data.

With limited resources, a sensible strategy for the grapevine community is to promote the use of existing international repositories for common data types , MetaboLights, PRIDE and so on, which already require submission of standards-compliant data, and to utilize these data in specialized services targeted at the specific needs of grapevine researchers. This has been the strategy of the grapevine community from its start regarding molecular data . For instance, 3971 grapevine transcriptomic data sets have been so far submitted to the GEO database . In turn, phenotypic data are not currently concentrated in any generic resource, nor is there an obvious repository to which submission can be recommended. The grapevine community must therefore assist in the coordination of multiple resources and should contribute to the definition of international standards in the domain. As many of the data will have features in common with those produced by other crop communities, coordination with wider initiatives such as the European Plant Phenotyping Infrastructure is a sensible course.Looking backward, the grapevine community has been increasingly active in the production of data in the life science area, as shown by a very naive search of recent publications in the PubMed database . The data described in the papers are very diverse covering genomes, genotypes, genomic variation, genetic maps, QTLs, association genetics, transcriptomics, proteomics, metabolomics, phenotype characterizations; and rapidly developing, with the quantity of data produced by a single experiment increasing rapidly over time. The development of a common policy for data standardization has lagged and this gap is impairing progress in grapevine research.The foundation of data sharing is to have a good understanding of what is about to be shared. For certain common types of experiments , agreement should be possible about the information that needs to be provided alongside the experimental results in order for that data to be useful and interpretable by others. This idea has been captured, for many experimental types, in ‘Minimum Information’ papers, in which the conceptual metadata needed to support an experiment of that type are defined. Among the metadata standards that might be of interest for the grapevine community are already in common use, including the Minimal Information About a Microarray Experiment ,now evolving into the Minimal Information about high-throughput SEQuencing experiments and the Minimal Information About Proteomic Experiments ,the Metabolomic Standards Initiative has developed a standard for Core Information for Metabolomics Reporting.Such papers have formed the basis for the subsequent development of exchange formats and databases. Others standards are still emerging like the Minimal Information for QTLs and Association Studies , the Minimal Information about a Genotyping experiment or the Minimal Information About Plant Phenotyping Experiments. Experimental metadata within-omics experiments can be conveniently standardized and shared with the ISA-Tab protocols.The success of these standards obviously depends on their adoption by the community, which is determined by many factors, such as its enforcement by publishers and the existence and ease-of-use of an associated toolset.Widespread adoption requires that correct formatting of data must be as simple as possible. On the other hand, if time consuming development of specific tools is required, there is a risk that a format will be slow to evolve, and at risk of being desynchronized with the needs of the data producers in a period where technologies are evolving very rapidly.Inevitably, the understanding of processes that underlie sustainable crop production under varying environmental conditions requires experimentation with a wide diversity of genetic material. This could include the use of mutants or individuals carrying extreme phenotypes to decipher physiological mechanisms, progenies derived from controlled crosses or diversity panels to determine the genetic control of trait variation, individuals collected in situ for the study of the adaptation of populations to environments, the evaluation of wild relatives and so on. In the grapevine community association studies, exploiting natural diversity through large-scale sequencing and phenotyping, have enormous potential to compensate for the lack of large mutant collections and are widely implemented to complement other approaches to support the identification of candidate genes for traits in physiological processes .

Routine inspection and cleaning of the area in front of a filter sock is important

When the pores become clogged with particulates, the pressure required to force the water through the substrate increases, therefore treated water volume is reduced unless pressure is increased. These systems must be back-flushed to remove collected particulates and maintain the effectiveness of the filter . Smaller particle size filter media clog more easily and require more frequent back-flushing. As the amount of particulates in the intake water increases, so does the frequency of back washing, which can waste water if it is not recaptured by the system. These systems do not remove most chemical and biological contaminants, but are mainly used to limit clogging of irrigation lines and emitters and to minimize inactivation of sanitation chemicals via sorption to non-target particulates .Disc filters are mechanical filters that typically handle smaller volumes of water per unit time than rapid sand filters . Disc filters can remove particles up to 150 μM and are used as primary filters when water is relatively free of particulates or if only small volumes need to be treated; when larger particulates may cause clogging , they can also serve as secondary filters behind rapid sand filters . Like rapid sand filters,arandanos cultivo they must be back washed periodically to clean particulates out of the discs.

Disc filters do not remove chemical contaminants or most pathogens from the water. Other types of mechanical filters are used for specific situations. Paper filters and rotary screens are typically used to remove sediment and large debris from water that is not typically under pressure. These systems are generally used in greenhouses to filter recaptured water from the operation.Activated carbon is not a stand-alone treatment and should be paired with another filtration system to increase treatment efficacy . Activated carbon has a large, porous internal surface area with filter pore sizes ranging from 10 to 500 μm and can be manufactured to desired particle size with a low acid/base reactivity. Activated carbon is positively charged and can adsorb organic, moderately polar compounds and negatively charged contaminants depending upon source material and pyrolysis, oxidation, and purification methods . The internal structure of activated carbon influences its capacity to adsorb contaminants . Activated carbon is used extensively in micropropagation applications to mitigate effects of inhibitory compounds on plantlet growth . As the volume of water per unit time increases, carbon filters become less effective because contact time with the activated carbon decreases. Water pH, ions present , and concentration of other contaminants also influence the efficacy of carbon filters . Activated carbon systems require periodic maintenance including replacement or regeneration of carbon once it has been saturated, which depends on water volume and contaminant loads.

Carbon filters remove some pesticides . Economic losses associated with stunted or deformed non-target crops can be attributed to presence of residual ancymidol or paclobutrazol at concentrations as low as 3 or 5 μg L−1 , respectively . Detection and remediation of plant growth regulators with activated carbon are currently being evaluated. The cost of the technology, along with its potential to remove beneficial compounds such as residual metals applied as fertilizer, may make its application less useful in some circumstances. Additional research on efficacy and economics of carbon filters would benefit growers, particularly in the area of plant growth regulator removal, which is a concern particularly in greenhouses.Membrane filters work by exerting pressure on water on one side of a membrane to sieve particles from the water stream . The permeate, or filtered water, is pushed through the filter while the retentate, or concentrated waste stream, must be disposed of or treated . Membrane filters facilitate removal of contaminants with particle sizes ranging from 0.1 to <0.0005 μm . Within this size range, filter classifications are defined by pore size and membrane pressures as identified in Table 2. The pore sizes of material from which membranes are derived differ and thus influence their applications and the types of contaminants that can be controlled. Membranes can become clogged over time and may require periodic remediation to manage fouling. Remediation may consist of back washing for micro-filtration and ultra-filtration or use of acid or alkaline detergents to mitigate inorganic or organic fouling, respectively . Membranes can be produced which avoid fouling by using pre-filters or membrane surface modifications, whether to alter hydrophobic/hydrophilic ratios for nano-filtration and reverse osmosis or to manage electrostatic attraction sources so membranes actively repel fouling agents .

Contaminant remediation using membrane filters is considered prohibitively expensive for use in most container production systems except in asexual plant propagation of high value crops—where high-quality water is critical, due to installation and maintenance costs, pumping costs, downstream processing costs, and rapid clogging of filters .Anionic, water-soluble polyacrylamide are long chains of linked acrylamide . They have been used since 1995 as an additive to reduce irrigation-induced sediment loss, promote infiltration, and induce flocculation and aggregation of suspended solids from irrigated production runoff . The PAMs used in agriculture contain less than 0.05% of acrylamide monomer, which is considered toxic to humans . Anionic PAMs are considered safe in the environment, as they have a low aquatic toxicity in comparison with cationic and non-ionic forms .Use of PAMs has primarily focused on mitigation of erosion, but when PAMs are used to flocculate suspended solids from water, they also remove any bound pesticide, phosphorus, and microbial residues that are adsorbed to those particles. Pesticide removal depends upon the chemistry of the compound; efficiencies depend upon the compound evaluated with removal averaging 78.7% for bifenthrin, 38% for bupirimate, 49% for atrazine, 49% for chlorothalonil, 54% for endosulfan, 84.2% of cis-permethrin, and 71.2% of transpermethrin , though it is difficult to differentiate between flocculation of sediment-bound pesticides and pesticide removal by PAM alone. Dissolved reactive phosphorus was not removed, but particulate P was . Sojka and Entry reported that PAM treatment reduced total algal, bacterial, fungal, and microbial biomass in irrigation water. Applying PAM during irrigation with rates as low as 1–2 kg/ha halted 94% of erosion from irrigated furrows and 92.9% sediment reduction when PAM was injected at 10 mg/L into nursery production runoff . Estimated cost per acre in 2008 was $10 to $30 per acre at these application rates .Filter socks are used primarily as a sediment trap or to retain some chemicals from construction site runoff, but in recent years filter socks have also been evaluated for mitigating sediments and agrichemicals from surface water runoff in agricultural fields . Filter socks can be filled with a variety of organic media, primarily composted wood chips,maceteros grandes reciclados that can be further amended with inorganic adsorbents/precipitants or synthetic additives such as PAM or other polymers to enhance flocculation, depending on their purpose . Filter socks cost between $3.50 and $15.00 per linear foot for continuous non-amended or amended filter socks, with amended socks having higher costs. Filter socks can provide significant sediment control when installed and maintained properly . Most filter socks have a relatively short lifespan of a few months to a year before they begin to saturate, break down, and lose their effectiveness; however, there are reusable/refillable Bflexible filter hand bags^ for catch basins which have been recently introduced . Filter sock flow-through rate, and subsequent ponding prior to the sock, is affected by substrate packing density and particle size . If sediment levels build up to the point where water crests the filter sock instead of flowing through it, the filters are less effective.Also, if the socks have poor contact with the ground, the volume of water is too large, or the slope is too steep, the filter sock can be bypassed, reducing treatment effectiveness. Hydraulic flow-through rate may better predict sediment and phosphorus removal than particle size distribution alone .

However, substrate particle size influences hydraulic flow-through rate; thus, both flow rate capacity and particle distribution are pertinent factors when designing filter socks for sediment control. Average removal percent efficiency of compost filter socks varies by contaminant and initial concentration or load , with concentration reductions reported for sediment , total and/or soluble phosphorus , or pesticides , and 18% for alachlor. Flow rate capacity and lifespan of filter socks are especially pertinent in nursery production areas, where uncontaminated water and production runoff events often flood roadways. The capacity of the filter socks to manage sediment, while remaining in place and not backing up water into production areas, is a critical design factor and requires further investigation. One option to investigate is alternate layouts that capture sediment without impeding flow, similar to stream restorations .The first step in irrigation water treatment is typically physical removal of macro-particles via filtration, followed by the addition of chemical disinfectants to reduce the spread of water-borne diseases. Chemical applications are more effective when carbon-based particulates are removed prior to chemical treatment, because organic compounds create a demand on active ingredient of chemical treatments . Chemical treatment efficacy declines if high levels of organic matter are present in water, necessitating higher concentrations of chemical to treat the same volume of water . Whereas filtration removes physical impurities from irrigation water that are larger than single-celled microbes, chemical treatment is targeted towards the removal of biological contaminants . Removal of pathogens and other biological organisms improves crop health and system longevity. This section covers some of the more commonly adopted disinfection technologies including chlorine, copper, peroxides, silver, ozone, and ultraviolet light. A review of a wide range of treatment technologies not discussed herein can be found in Raudales et al. .The most commonly used chemical treatment is chlorination either as a solid , liquid , or gas or generated through an electrolysis process. The presence of 0.5 to 2 ppm of free chlorine at the sprinkler head is recommended to ensure adequate sanitation . Chlorine levels should be routinely checked during crop production, as changes in water quality and the amount of organic matter in treated water impact the chlorine residual that will exit the sprinkler head. Hypochlorous acid , the most important sanitizing form of dissolved chlorine, is favored over the weaker hypochlorite form at pH below 7.5. Therefore, acidification of irrigation water is often desirable prior to chlorine injection to increase chlorine efficacy. Many operations use chlorine for disinfection because of its cost effectiveness and relative ease of use. The major concern with chlorine is the additional safety precautions that are required for its use, which vary by type of chlorine. Extensive discussions related to efficacy, dose, costs and benefits, and timing of chlorine injection are available in Newman , Raudales et al. , and Stewart-Wade .Ozone is a strong oxidant that disinfects by producing a reduction-oxidation reaction in pathogens and other organic constituents . An ozone production system uses electricity to split oxygen molecules to form ozone . Ozone breaks down into peroxides and other oxygen radicals, providing additional disinfection. No additional inputs are required, and no persistent by-products are produced. Ozone and by-products degrade quickly in water, so direct testing is difficult, but in-line monitors that also control injection concentration are typically employed . Ozone activity is reduced in the presence of organic matter, high pH, and/or high concentrations of nitrite, manganese, iron, or bicarbonate . For a high level of disinfestation, Runia reported that a dose of 10 g O3/m3 water with a 1-h contact time at a pH 4 resulted in kill of 99.9% of bacteria and fungi. However, this process requires injecting ozone into a storage cistern rather than in-line injection, as can be used for other chemical treatment technologies. Other studies with ozone have varied contact times , with effective control achieved with ozone doses ranging from 0.01 ppm O3 for algae control to 1.6 ppm O3 to control Phytophthora cinnamomi chlamydospores and 1.75 ppm O3 to kill Fusarium oxysporum conidia . Ozone is one of the most expensive water treatment options in terms of installation cost, with electricity being the main operating cost . Potential human health effects from ozone exposure require fail-safes and adequate venting, thus reducing the popularity of ozone for treating pathogens in irrigation water .Slow sand filters have been used since 1804 to cleanse contaminants from water for both drinking water and industrial uses and have been adopted by the European horticultural community to remove phytopathogens from reused irrigation water since the early 1990s .

Import liberalization has been a theme stressed in many of the above mentioned papers

The 2020 yield data confirmed our assumption, as the harvested olives per row were similar within each block . This suggested that ReTain™ did have an effect on olive yield. However, this effect may have been masked by heavy rain and cold temperatures in May 2019. During the “off” year of 2020, ReTain™ seemed to have a greater effect in improving yield in the orchard with less inflorescences , than in the orchard with more inflorescence . There was no difference in any oil quality indicators between ReTain™-treated and control fruits . We hypothesized that a foliar ReTain™-application would depress ethylene synthesis by olive flowers, delay floral senescence and increase the effective pollination period, allowing a higher rate of successful fertilization. We monitored ethylene generation after foliar ReTain™ application, evaluated floral senescence visually and evaluated pollen tube growth to indicate pollination, weighed yield to determine whether fruit set was higher, and measured oil quality to determine whether oil quality was affected. Foliar application of ReTain™ at 25 to 50% full bloom significantly and consistently reduced ethylene synthesis by olive flowers in an “on”, heavily-cropped year, and the yield was significantly improved under a 0.1 alpha value. However,macetas redondas determining whether this increased yield was caused by having a longer effective pollination period was inconclusive.

The visual rating of flower senescence did not support our hypothesis: ReTain™-treated flowers senesced earlier than control flowers. As indicated by pollen tube growth, successful pollination was unaffected as the pollen tubes were unobservable after they passed down the styles. It was unclear whether ovule viability was prolonged. This experiment was conducted only for a single year in this alternate-bearing crop, because there were insufficient flowers the second year. Repeating this trial under better conditions, such as optimal temperatures and no rain during pollination, may produce more consistent effects on yield. Also, developing a more discriminating method to measure pollen tube growth, their successful access to ovules, pollination, and perhaps pollen and ovule viability could better determine how ReTain™ produced a significant increase in yield. Over the past decade, the annual U.S. trade balance with China has gone from a small surplus to a deficit of over $57 billion . The mounting trade deficit has resulted in renewed U. S. pressure to expand access to China’s markets. Recently, there have been intensive U.S.-China discussions over trade concessions and the related issue of China’s bid to join the World Trade Organization . Agricultural trade is at the center of these negotiations as China’s high trade barriers in agriculture are believed to be partly responsible for the trade deficit.In a typical year, China has neither a large surplus nor a large deficit in its agricultural trade balance. For instance, in 1995, China ran a relatively small agricultural trade deficit of $1.47 billion and then in 1996 the balance shifted to become a small surplus, with agricultural exports exceeding imports by $673 million in that year.Even though its overall agricultural trade balance is small, China is a significant but erratic trader for certain agricultural commodities such as wheat, maize, oil seeds, edible oils, tobacco and cotton. China’s agricultural trade regime has not been liberalized to the same extent as its trade in manufactures .

So there is great uncertainty as to what might happen if and when China liberalizes its agricultural trade. Some projections suggest that China will become a consistent net importer of food . Based on its large and growing population and fluctuating grain stockpiles, some fear that China could destabilize world markets after agricultural trade liberalization . Agricultural trade barriers will be a key issue with regard to China’s application to join the World Trade Organization . For instance, China’s non-tariff trade barriers in grains are very controversial. The barriers in grains are not transparent because China’s state trading in grains is conducted through its Cereal, Oil, and Foodstuffs Importing and Exporting Corporation . COFCO is one of the world’s largest STEs in agriculture, and over the past decade, COFCO has imported as much as 17 percent of world wheat traded, and exported as much as much as 10 percent of the world’s corn. The reemergence of China as a significant trading nation in merchandise trade has been described by West , Lardy , World Bank , Wall, Boke, and Xiangshou , and Naughton . Greater integration with the global economy began in the mid 1980s and is now recognized as a fundamental feature of China’s ongoing economic reform.As a measure of openness, China’s nominal value of exports grew by 13 percent annually from 1980 to 1996. During the same time period, imports grew by 12 percent per year, on average. By 1997, China’s total trade accounted for about 3 percent of world trade, up from 0.8 percent in 1978. However, the degree to which China’s door is open to the world is debatable and China may be less open to foreign trade than initially appears . From 1986 to 1996, China’s growth in real merchandise trade exceeded growth in real GDP by 2.1 percent, which was not particularly high by international standards. For instance, during the same time period, growth in real trade less growth in real GDP was 6.9 percent in Thailand and 4.5 percent in the United States.China’s ratio of foreign trade to GDP rose from 13 percent in 1980 to about 35 percent in 1996, valued at the official exchange rate.

However, this ratio may overstate the relative importance of foreign trade in China’s economy because it is based on the official exchange rate . If instead, the purchasing power parity exchange rate is used, trade as a percent of GDP has not changed all that much since the mid 1980s. Using the real exchange rate, China’s trade as a percent of GDP only grew slightly from 6.6 percent in 1986 to 7.1 percent in 1996 . In relative terms, India’s trade as percent of GDP grew faster than China’s over this time period, going from 3.9 percent to 4.5 percent. In comparison, Thailand’s trade as a percent of GDP grew from 14.7 percent to 31.3 percent from 1986 to 1996. Despite China’s move to lower average tariffs, China continues to restrict imports through a variety of barriers, including tariff-quotas, taxes, import quotas, import licenses, and state trading . In addition, China uses other non-tariff technical trade barriers such as sanitary and phytosanitary measures. These barriers are commonly applied to agricultural products. For instance, under the guise of phytosanitary measures, China prohibits imports of U.S. citrus.Lardy explains that the commodity composition of trade has changed along with domestic market reforms, and that trade patterns are more consistent with China’s comparative advantage, compared with the pre-reform and early reform time periods. China has shifted away from petroleum exports and has increased exports of labor-intensive manufactured goods,maceta de 10 litros to the point where manufactured goods accounted for 85 percent of exports in 1996. The share of primary commodities in total imports fell from a little over one-third in 1980 to about one-fifth by 1996. China’s agriculture has a comparative advantage in labor intensive crops, not grains . However, policy has tilted China’s agricultural production away from its comparative advantage which lies in non-grain activities. Naughton argues that China’s merchandise exports have shifted to reflect its abundant labor. Has this happened in agriculture? To what degree is agricultural production and trade becoming more specialized to capture its comparative advantage in labor intensive food products? From a conceptual basis, Anderson argued that China’s economic reform would have a significant impact on the pattern of agricultural trade. More recently, the same argument has been made from an empirical perspective by Wang and Wailes, Fang, and Tuan . Wailes, Fang, and Tuan point out that the growth rates for China’s agricultural trade are much slower than for total trade and consequently the share of agricultural trade in total trade has declined quite dramatically. However, Wailes, Fang, and Tuan also argue that China’s agricultural trade has expanded rapidly and that the pattern of trade roughly adheres to the laws of comparative advantage. Alternatively, Anderson and Strutt find there has been little growth in China’s food import dependence. Wang has argued that China’s agricultural net trade structure is consistent with its resource endowment. He found that land-intensive bulk4 and processed intermediate commodities account for most of the imports, while labor-intensive horticultural and consumer ready products make up most of the agricultural exports. However, he based his analysis on 1995 and 1996 data, a periodduring which China had a temporary export blockage on grain exports. In late 1994, the central government placed a moratorium on grain exports in an effort to control higher domestic food prices. Rice and maize have traditionally been net exports but they shifted to a net import situation during the export blockade.

Yiping Huang has argued that economic reforms in China have generated a significant impact on agricultural trade. He supported this observation with three points. His first point was that the growth of exports outpaced that of GDP during the reform period. Second, he noted that distortions to agricultural trade have been reduced significantly and agricultural trade experienced dramatic expansion. Third, he noted that trade was brought into conformity with the pattern of resource endowments.The trade reforms that have been implemented in China since 1979 are characterized by demonopolisation of foreign trade, the phasing out of trade subsidies, replacing of planned-quotas with a tariff- quota regime , progress toward currency convertibility, and provisions to attract foreign direct investment. The opening-up has been a means to promote economic growth and conform with general international trade rules so as to finally join the WTO. In general, some significant changes in the nature and extent of government trade interventions have occurred in China. Prior to the reform period, the allocation of imports and exports were strictly based on administrative planning and undertaken by only 12 foreign trade corporations. The process of trade policy reform has involved the introduction of some competition in international trading and the gradual development of policy instruments for indirect controls. In 1984, the foreign trade system was decentralized considerably, when the provincial branches of national foreign trade corporations were allowed to become independent and each province was allowed to create its own FTCs. By 1986 there were about 1,200 FTCs, and by the early 1990’s they numbered more than 3,000. Although firms must obtain approval to engage in international trade, this permission has been granted very liberally and there are now approximately 200,000 firms eligible to engage in foreign trade . On the other hand, the foreign trade of so-called “strategic products” such as food grains, textile fibers, and chemical fertilizers, continue to be restricted to specialized national trading corporations with monopoly trading rights. China’s agricultural trade policy, particularly with regard to grain, is characterized by import/export licenses and quotas. But even in the case of agricultural trade, some progress has been made since the 1980s. The overall purpose of this paper is to measure this progress, relative to trade in manufactures and other primary commodities. Prior to the 1978 reforms, almost all of China’s foreign trade was subject to central planning through a small number of foreign trade corporations. For most sectors, the government has since replaced central planning over trade with import licenses and import and export tariffs. The opening of China’s economy involved policies to promote exports and attract foreign direct investment. However, agricultural trade is a major exception to this move towards decentralization of foreign trade. This is somewhat ironic because agriculture was largely responsible for the initial success of China’s overall economic reform.In China, rapid economic growth has been accompanied by dramatic changes in the structure of the economy. Agriculture’s share in the total economy has declined from about 40 percent of the GDP in 1970 to less than 20 percent in 1997. At the same time, agriculture’s share in total employment declined from 81 percent to 49 percent.The declining role of agriculture in the economy means the share of agricultural trade in China’s total trade has decreased significantly. In 1980, agriculture’s share of both exports and imports was around 30 percent, and this declined to about 10 percent in 1997.

A key resource to secure in this process is nitrogen, a raw material needed to produce proteins

Glutamate synthase plays a vital role in nitrogen metabolism, and its ortholog in the ascomycete Magnaporthe oryzae MoGLT1 is required for conidiation and complete virulence on rice. GMC oxidoreductase exhibits important auxiliary activity 3 according to the Carbohydrate-Active enzymes database and is required for the induction of asexual development in Aspergillus nidulans. An extensive approach was used for the global annotation of CAZyme genes in P. pachyrhizi genomes, and after comparison with other fungal genomes, we also found clear expansions in glycoside hydrolases family 18 and glycosyltransferases family 1 . GH18 chitinases are required for fungal cell wall degradation and remodelling, as well as multiple other physiological processes, including nutrient uptake and pathogenicity. The Phakopsoraceae to which P. pachyrhizi belongs represents a new family branch in the order Pucciniales1 . With three P. pachyrhizi genome annotation replicates available, next to the above CAFÉ-analysis, we can directly track gene family expansions and contractions in comparison to genomes previously sequenced. We, therefore, compared P. pachyrhizi to the taxonomically related families Coleosporiaceae, Melampsoraceae and Pucciniaceae, which in turn may reveal unique lifestyle adaptations . The largest uniquely expanded gene family in P. pachyrhizi comprises sequences containing the Piwi domain . Typically, the Piwi domain is found in the Argonaute complex, where its function is to cleave ssRNA when guided by dsRNA. Interestingly, classes of longer-than-average miRNAs known as Piwi-interacting RNAs that are 26-31 nucleotides long are known in animal systems.

In Drosophila, these piRNAs function in nuclear RNA silencing,hydroponic growing systems where they associate specifically with repeat-associated small interfering RNA that originate from TEs. As in other fungal genomes, the canonical genes coding for large AGO proteins with canonical Argonaute, PAZ and Piwi domains can be observed in the genome annotation of the three P. pachyrhizi isolates. The hundreds of expanded predicted Piwi genes consist of short sequences of less than 500 nt containing only a partial Piwi domain aligning with the C-terminal part of the Piwi domain in the AGO protein. Some of these genes are pseudogenes marked by stop codons or encoding truncated protein forms, while others exhibit a partial Piwi domain starting with a methionine and eventually exhibiting a strong prediction for an N-terminal signal peptide. These expanded short Piwi genes are surrounded by TEs, several hundreds of which, but not all, are found in close proximity to specific TE consensus identified by the REPET analysis in the three P. pachyrhizi isolates . However, no systematic and significant association could be made due to the numerous nested TEs present within the genome. Moreover, none of the expanded short Piwi domain genes are expressed in the conditions we tested. However, in many systems, Piwis and piRNAs play crucial roles during specific developmental stages where they influence epigenetic, germ cell, stem cell, transposon silencing, and translational regulation. Finally, the domain present in these short Piwi genes is partial, and we do not know whether they retain any RNase activity. Therefore, we cannot validate at this stage the function of this family, which warrants further study and attention as it may represent either a new type of TE-associated regulator within P. pachyrhizi, or an expansion of a control mechanism to deal with this highly repetitive genome. Several families related to amino acid metabolism have expanded greatly when compared to the respective families in other rust fungi, most notably Asparagine synthase , which has ~75 copies in P. pachyrhizi compared to two copies in Pucciniaceae and one copy in Melampsoraceae .

Similarly, expanded gene families can be observed in citrate synthase , malate synthase , NAD-dependent malate dehydrogenase . These enzymes are involved in energy production and conversion via the citrate cycle required to produce certain amino acids and the reducing agent NADH . Next to the molecular dialogue with effector proteins, plantpathogen interactions are a “tug-of-war” of resources between the host and the pathogen.Therefore, the expansion in amino acid metabolism may reflect an adaptation to become more effective at securing this resource. Alternatively, the expanded categories also may reflect the metabolic flexibility needed to facilitate the broad host range of P. pachyrhizi, which to date comprises 153 leguminous species in 56 genera. Associations with TEs are often a sign for adaptive evolution as they facilitate the genetic leaps required for rapid phenotypic diversifification. Gene duplication and gene family expansion can be directly linked to transposition activity due to imprecise excision and re-insertions and carry other genetic sequences. Transposition independent mechanisms may also promote structural rearrangements leading to gene family expansions through the recombination of homologous regions between TE copies. The TEs in these expansions may potentially be inactive. We, therefore, investigated whether the expansion in amino acid metabolism could reflect a more recent adaptation by studying the TEs in these genomic regions. Furthermore, as described above, a distinction can be made between more recent bursts of TE activity and older TE bursts leading to degeneration of the TE sequence consensus. However, despite the presence of several copies of specific TE subfamilies in the vicinity of the surveyed expanded families such as amino acid metabolism, CAZymes and transporter related genes , no significant enrichment could be observed for any particular TE when compared to the overall TE content of the genome.

This may reflect the challenge of making such clear associations due to the continuous transposition activity, which results in a high plasticity of the genomic landscape and a highly nested TE structure. Alternatively, it may suggest a more ancient origin of these expansions that have subsequently been masked by repetitive episodes of relaxed TE expression .The high molecular weight genomic-DNA was extracted using a carboxyl-modified magnetic bead protocol for K8108, a CTAB-based extraction for MT2006, and a modified CTAB protocol for UFV02. For K8108, a 20-kb PacBio SMRTbell library was prepared by Genewiz with 15-kb Blue Pippin size selection being performed prior to sequencing on a PacBio Sequel system . The K8108 PacBio Sequel genomic reads yielding 69 Gbp of sequence data were error corrected using MECAT; following parameter optimization for contiguity and completeness, the longest corrected reads yielding 50x coverage were assembled with MECAT’s mecat2canu adaptation of the Canu assembly workflow, using an estimated genome size of 500 Mbp and an estimated residual error rate of 0.02. The resulting assembly had further base pair-level error correction performed using the Arrow polishing tool from PacBio SMRTTools v5.1.0.26412. MT2006 genome was sequenced using the Pacific Biosciences platform. The DNA sheared to >10 kb using Covaris g-Tubes was treated with exonuclease to remove single-stranded ends and DNA damage repair mix, nft system followed by end repair and ligation of blunt adapters using SMRTbell Template Prep Kit 1.0 . The library was purified with AMPure PB beads and size selected with BluePippin at >6 kb cutoff size. PacBio Sequencing primer was then annealed to the SMRTbell template library, and sequencing polymerase was bound to them using Sequel Binding kit 2.0. The prepared SMRTbell template libraries were then sequenced on a Pacific Biosystem’s Sequel sequencer using v2 sequencing primer, 1 M v2 SMRT cells, and Version 2.0 sequencing chemistry with 1 × 360 and 1 × 600 sequencing movie run times. The Phakopsora pachyrhizi MG2006 v1.0 genome was sequenced with PacBio, assembled with MECAT, polished with arrow, and annotated with the JGI Annotation Pipeline. For UFV02, the PromethION platform of Oxford nanopore technology  was used for long-read sequencing at KeyGene N.V. . The libraries with long DNA fragments were constructed and sequenced on the PromethION platform. The UFV02 genome assembly, the longest 15, 20, 25, 30, 34, 40 and 56x nanopore reads were assembled using the Minimap2 and Miniasm pipeline. To improve the consensus, error correction was performed three times with Racon using all the nanopore reads. The resulting assembly was polished with 50x Illumina PCR-free 150 bp paired-end reads mapped with bwa and Pilon, and repeated three times. We assessed the BUSCO scores after each step to compare the improvement in the assemblies.The gene predictions and annotations were performed in the P. pachyrhizi genomes K8108, MT2006 and UFV02 in parallel using the JGI Annotation Pipeline.

TE masking was done during the JGI procedure, which detects, and masks repeats and TEs. Later, the extensive TE classification performed with REPET was imported and visualized as a supplementary track onto the genome portals. RNAseq data from each isolate was used as intrinsic support information for the gene callers from the JGI pipeline. The gene prediction procedure identifies a series of gene models at each gene locus and proposes the best gene model to define a filtered gene catalogue. Translated proteins deduced from gene models are further used for functional annotation according to international reference databases. All the annotation information is collected into an open public JGI genome portal in the MycoCosm with dedicated tools for community-based annotation. In total, 18,216, 19,618 and 22,467 gene models were predicted from K8108, MT2006 and UFV02, respectively ; of which 10,492, 10,266 and 9,987 genes were functionally annotated. We have performed differential expression analyses using the germinated spores as a reference point in each of the three isolates . A total of 3,608 common differentially expressed genes were identified in at least one condition shared between two or more isolates .For expression analysis, 11 different stages were evaluated, with eight stages having an overlap of two or more isolates. These stages were nominated 1-11, as illustrated in Fig. 3c. For K8108, seven in vitro, one on planta and eight in planta samples, each with three biological replicates, were generated and used to prepare RNA libraries. To get in vitro germ tubes and fungal penetration structures, a polyethylene foil was placed in glass plates and inoculated with a spore suspension . Each biological replicate corresponded to 500 cm² foil and ~4 mg urediospores. The plates were incubated at 22 °C in the dark at saturated humidity for 0.5, 2, 4 or 8 h. After incubation, the spores were collected using a cell scraper. For the appressoria-enriched sample, urediospore concentration was doubled and the plates rinsed with sterile water after 8 h of incubation prior to collection. The material was ground with mortar and pestle in liquid nitrogen. The time 0.5 h was considered as spore , the 2 h as a germinated spore , and the 8 h rinsed as appressoria enriched sample in vitro . The samples of spores collected after 4 and 8 h were not used for expression analysis. To obtain on planta fungal structures, three-week-old soybean plants were inoculated as mentioned above. After 8 HPI, liquid latex was sprayed until complete leaf coverage. After drying off, latex was removed. It contained the appressoria and spores from the leaf surface but no plant tissue. This sample was considered as enriched in appressoria on plant and is exclusive for K8108 isolate . Three middle leaflets of different plants were bulked for each sample and ground in liquid nitrogen using a mortar and pestle. The inoculated leaf samples were harvested at 10, 24, 72 and 192 HPI for the in planta gene expression studies. For MT2006, the germ tubes, and appressorium were produced on polyethylene sheets where urediospores were finely dusted with household sieves held in a double layer of sifting. The PE sheets were then sprayed with water using a chromatography vaporizer and were kept at 20 °C, 95% humidity in the dark. For germ tubes the structures were scratched from the PE sheets after 3 h and for appressoria after 5 h . The formation of both germ tubes and appressoria was checked microscopically. The in vitro samples were only used when there were at least 70% germ tubes or appressoria. The structures were dried by vacuum filtration and stored in 2-ml micro-centrifuge tubes at −70 °C after freezing in liquid nitrogen. The resting spores came directly from storage at −70 °C . For the in planta samples, 21 days old soybean cultivar Thorne was sprayed with a suspension containing 0.01% Tween-20, 0.08% milk-powder and 0.05% urediospores. The inoculated plants were kept, as mentioned previously.

Biological regulation was over represented among down regulated GO terms

Nitrate at this depth is neither available for trees, since the majority of active fibrous roots of orange trees are in the top 15–30 cm depth , nor can it be easily transformed because of the limited microbial population and available carbon at this depth . This can potentially lead to eventual leaching losses to receiving water bodies. Hence over-irrigation not only led to a profound water loss, but also brought about a reduction in plant nitrogen uptake and an increase in potential danger of appreciable NO3-N leaching losses in all fertigation scenarios. Therefore, the combination of inadequate management of irrigation and nitrogen fertilizers in commercial agriculture may lead to considerable nitrate losses out of the root zone, and may increase the risk of nitrate contamination of ground water aquifers.Petal senescence is the irreversible and final stage of floral differentiation and development, associated with dynamic alterations once a flower has been successfully pollinated. However, it is not clear how the process is regulated genetically. Homeostasis or alterations of plant hormones is involved in the onset of floral senescence. In ethylene -sensitive flowers, the first sign of visible senescence is accompanied by a transient and sudden rise of ET production. Other hormones such as cytokinin, abscisic acid , auxin, gibberellic acid,hydroponic nft system and jasmonic acid are also involved in ET-sensitive petal senescence. ABA accelerates petal senescence.

Treatment with ABA promotes the large increase in ET production and hastens petal wilting in carnation flowers. Pretreatments with silver thiosulfate , a chemical that inhibits the perception of ET by the ET receptor, completely prevents the increase in ABA levels. A negative relationship was observed between the level of CKs and petal senescence in petunia and carnation. In rose, the increase of CK content antagonized petal senescence prompted by ET. Applying CKs delayed petunia petal senescence. Auxin also plays a role in ET-sensitive petal senescence. Application of auxin prompted ET production and petal wilting in cut carnation flowers. In addition, 2,4-dichlorophenoxyacetic acid , a synthetic auxin, induced the expression of 1-aminocyclopropane-1-carboxylic acid synthase genes in petals. In most research, these hormones are used as exogenous regulators to observe ET sensitivity and floral longevity in ET-sensitive species. Although the enrichment of ‘response to 1-aminocyclopropase-1- carboxylic acid and auxin stimulus’ was observed 12 h after pollination in the petals of petunia, the differential expression patterns of genes related to these hormones in petal senescence is unclear. Petal senescence is regulated by transcription factors . On one hand, ethylene-insensitve-like and ethylene response factors are correlated with the ET response signaling pathway. EIL3, a homolog of ETinsensitive 3 in carnation, is a pivotal switch of ET induced gene expression. DAFSAG9, which is homologous to ERF2, was significantly upregulated in senescing daffodil petals. On the other hand, a large group of other TFs, such as B-box zinc finger, bHLH DNA-binding, homeodomain-like , MADS-box, MYB, and NAC, display differential expression when ET-insensitivity is induced in the etr1-1 transgenic petunia. More than 20 members from the ERF, NAC, bZIP, HD-Zip, and WRKY TF families showed differential expression in petals at the early stage of pollination-induced senescence in petunia.

In addition, NAC, Aux/IAA, MYB, bZIP, and MADS-box are differentially expressed during carnation petal senescence. These studies indicate that these TFs play regulating roles in ET-dependent petal senescence. However, the biological functions of these TFs are largely unknown. High-throughput gene expression analysis using messenger RNA sequencing represents the most powerful tool to elucidate the underlying regulatory mechanism of corolla senescence. Recently, pollination- and ET-induced corolla senescence in petunia has been studied through RNA-Seq analysis16,20, however, the regulatory mechanisms that govern the onset of natural corolla senescence from opening to wilting in petunia is unclear. Therefore, identifying the dynamic processes and regulatory factors in transcription is a crucial step in determining the master switches in corolla senescence. We employed RNA-seq technology to investigate the global and chronological sequence of transcriptional events during the initial corolla senescence in petunia. Furthermore, virus-induced gene silencing system was used to dissect biological functions of potential regulatory genes such as TFs. Our data suggest that hormonal interactions between auxin and ET may play a critical role in the regulation of onset of corolla senescence in petunia.One microgram of total RNA was reverse-transcribed using PrimeScript RT reagent with gDNA Eraser Kit , according to the manufacturer’s instructions. Specific primers were designed by the Primer 3 program and listed in Supplementary Table S1. Amplifications were performed in an Applied Bio-systems 7300 system . Melting curve analysis was performed and the absence of non-specific products and primer dimers were verified. For data analysis, average threshold cycle values were calculated for each gene of interest, on the basis of three independent biological samples and were normalized and used to calculate relative transcript levels as described elsewhere. 26S ribosomal RNA was used as an internal standard for normalization.ET emission was monitored using a laser-based ET detector and a gas handling system as described previously. Briefly, flowers collected at D0 were placed into 70 ml sealed glass vials.

The air was passed through a platinum-based catalyzer before entering the cuvettes in order to remove external ET and other hydrocarbons. A scrubber with KOH and CaCl2 was used to reduce the CO2 and the water content in the gas flow. ET emission was monitored and recorded in real time. Three biological replicates of every flowering stage were performed. Each experiment was repeated three times.To measure longevity of intact flowers, white flowers from pTRV/CHS-TFs inoculated petunia ‘Primetime Blue’ plants were tagged at D0. The time when the corollas wilted and the edges collapsed was recorded. At least 20 flowers of three plants from each of the three independent biological replicates were monitored. Purple flowers from water-inoculated wild-type and white flowers from pTRV/CHS-silenced plants were used as controls. Statistical analyses were performed using the SPSS package . One-way analysis of variance was performed for experiments with one independent variable. Duncan’s test was used as the post hoc test if significant differences were found.Flowers that were fully opened but anthers not yet dehisced were marked as D0. The corollas continued to expand for 2 days. Visible senescence symptoms, such as curving of the corolla edges,nft channels were observed at an average of 4 days. Corolla wilting was found at about 7–8 days . We measured ET production using a real-time ET detection system, EDT-300. An increase and decrease of ET emission was detected during D2–D7 stage. The level spiked around D4, reaching the maximum level at 5.5 days, and then decreasing sharply .In order to determine the alteration in gene expression during corolla senescence, we generated cDNA libraries composed of the samples collected from four developmental stages with two biological replicates. RNA sequencing of these libraries produced 49,421,030, 52,985,600, 47,813,446, and 56,552,704 clean reads at D0, D2, D4, and D7, respectively . The sequences were mapped to the P. axillaris reference genome for annotation of all unigenes. The mapping rate was over 93% for samples of each stage . Differential expression analysis was conducted by comparing four different developmental stages. Analysis on all four stages generated 5167 unigenes that were significantly differentially expressed across these stages. The number of DEGs was decreased from 4626 between D0 and D2, to 1116 between D2 and D4, and to 327 between D4 and D7 . DEGs were clustered to generate expression patterns based on time series using the STEM software. Cluster analysis of the data from four time points generated 26 clusters, including down regulated genes in clusters 0 through 12 and upregulated genes in clusters 13 through 25 . A few clusters displayed a more complex pattern. For instance, clusters 2, 5, 7, 8, and 11 showed an initial decrease followed by upregulation. However, clusters 14 and 17 exhibited an initial increase followed by a decline . In addition, the down regulated clusters 3 and 4 and the upregulated clusters 15, 16, 21, 24, and 25 were statistically significant .In order to identify up and down regulated GO at each selected time point, seven gene clusters exhibiting either significantly decreased or increased expression were further analyzed using Cytoscape software with its GO enrichment tool BiNGO. At the transition from D0 to D2, the metabolic processes of major macro-nutrients including ‘carbohydrates, lipids, aromatic amino acids, and nitrogen compounds’ were down regulated . In addition, ‘cell wall organization and bio-genesis’, ‘Sadenosylmethionine biosynthesis’, and ‘negative regulation of transcription, DNA-dependent’ and ‘RNA metabolism’ were down regulated . However, ‘CK pathway’, ‘RNA modification’, ‘macromolecule methylation’, ‘DNA metabolism’, ‘ATP activity’, and ‘S-adenosylmethionine-dependent methyltransferase activity’ were upregulated . At the transition from D2 to D4, ‘monosaccharide metabolism ’, ‘polysaccharide metabolism ’, ‘lipid catabolism’, ‘amino acid metabolism ’, ‘Sadenosylmethionine biosynthesis’, and ‘L-phenylalanine biosynthesis’ were significantly upregulated . ‘Response to auxin stimulus’ was also significantly upregulated .

Down regulated GO terms were mainly ‘nicotianamine metabolism and biosynthesis’ .At the transition from D4 to D7, ‘iron ion binding’ was significantly upregulated. The only down regulated biological process was the auxinmediated signaling pathway . The over representation of ‘ribosome and cytosolic small ribosomal subunit’ was also enriched in the down regulated GO group .ET is a key flower senescence promoting hormone in ET-sensitive species. In this study, transcriptional dynamics at four distinct developmental stages of corollain petunia were monitored. The ‘S-adenosylmethionine biosynthesis’ GO term was significantly upregulated at the D2 and D4 transition . Expression of ACS and ACO genes was upregulated through D2 to D4 and D4 to D7 transitions. The increase of ET emission was initially detected at the D2 to D4 transition, while the spike of ET emission occurred at the D4 to D7 transition . These data suggest that early onset of corolla senescence may occur in the transition from D2 to D4, and execution of senescence takes place in the transition from D4 to D7.Notably, large alterations in abundances of auxinrelated transcripts occurred throughout the four developmental stages, especially through the transition from D2 to D4. Although, at present, the role of auxin in plant senescence remain poorly defined, and contrasting observations have been obtained from different species. Several studies have reported an involvement of auxin in the process of senescence, especially in petal senescence. For example, in cut carnation flowers, exogenous application of IAA hastened the rise in ET production and flower wilting. 2,4-dichlorophenoxyacetic acid , a synthetic auxin, induced the expression of ACC synthase genes in the styles, ovaries, and petals. It was reported that in the corollas of pollinated petunias, ‘response to auxin stimulus’ and ‘response to ACC’ were significantly enriched at 12 hap. Interaction between auxin and ET occurred at the early stage of pollination. Furthermore, the interaction between ET and auxin was also reported in ET-induced corolla senescence in petunia. Interestingly, during pear ripening, the auxin-associated transcripts are significantly upregulated in the S2 to S3 transition before pear ripening and down regulated in the S3 to S4 transition. In addition, auxin level declined prior to ripening in tomato, grape, and strawberry fruit. Moreover, the largest number of DEGs related to auxin were observed in the abscission process of rose petal. Down regulation of RhIAA16 by VIGS in rose promoted petal abscission. In our transcriptome data, DEGs in the auxin pathway, including auxin-responsive genes , auxin-induced genes , and auxin efflux carrier were all induced at the D2 to D4 transition, where ET production was increased. However, those auxin-related genes were down regulated in the D4 to D7 transition , while expression of ACO and ACS genes was upregulated and ET production reached a peak at 5.5 days . Taken together, we postulate that auxin might play common and vital positive roles in activating ET production and regulating developmental process that lead to subsequent attainment of ripening, senescence, and abscission capacity.Ecolabels are part of a new wave of environmental policy that emphasizes information disclosure as a tool to induce environmentally conscious behavior by both firms and consumers. The goal of ecolabels is to provide easily understood information and thereby elicit increased demand for products perceived as environmentally friendly. An important concern among consumers is that ecolabeled products might entail a trade-off between product quality and environmental impact. In other words, in order to achieve low environmental impact, green products would have to be of lower quality. In this study, we use the case of ecocertification in the wine industry to test the link between environmentally friendly production and product quality.

How Tall Does Lettuce Grow Ina Nft System

The height that lettuce can grow in an NFT (Nutrient Film Technique) system can vary depending on the specific lettuce variety, growing conditions, and the duration of growth. However, lettuce typically doesn’t grow very tall in an NFT system compared to other crops.

Most lettuce varieties are considered compact and have a relatively short stature. They are often harvested when they reach a certain size, rather than allowing them to grow to their maximum height. In an NFT system, the focus is usually on growing lettuce for its leaves rather than allowing it to bolt and produce a flowering stalk.

On average, lettuce plants in an NFT system typically reach a height of 20 to 30 centimeters (8 to 12 inches) before they are harvested. At this stage, the outer leaves are usually harvested, and the plant continues to produce new leaves from the center.

It’s worth noting that there are different lettuce varieties available, including compact or mini varieties, as well as larger, more elongated varieties. The specific lettuce variety you choose to grow in your NFT system may affect its height and growth characteristics.

Ultimately, the height at which lettuce grows in an NFT hydroponic system will depend on the specific variety, environmental conditions, and the desired stage of harvest. Regular harvesting and pruning of outer leaves will help maintain the plant’s height and promote continued growth.

How To Build A Hydroponics Growing System Using Pvc Pipes

Building a hydroponics growing system using PVC pipes is a popular and cost-effective method. Here’s a general guide to help you get started:

Materials needed:

  • PVC pipes (4-6 inches in diameter)
  • PVC fittings (elbows, tees, couplers)
  • PVC glue
  • Net pots or cups
  • Growing medium (such as perlite, vermiculite, or coconut coir)
  • Submersible pump
  • Tub or reservoir for nutrient solution
  • Air pump and air stones (optional)
  • Timer (for pump control)

Step-by-step instructions:

  1. Design your system: Determine the size and layout of your hydroponics system based on available space and the number of plants you want to grow. Plan for the main pipe, vertical growing tubes, and nutrient delivery system.
  2. Assemble the frame: Use PVC pipes and fittings to create the frame of your system. Construct a sturdy base and vertical supports to hold the growing tubes. Ensure the frame is level and stable.
  3. Create the vertical growing tubes: Cut the PVC pipes into sections of suitable length for your plants. These pipes will hold the net pots or cups. Drill holes evenly spaced along the length of each pipe, ensuring they are large enough to accommodate the net pots.
  4. Attach the growing tubes: Attach the vertical growing tubes to the frame using PVC fittings. Use elbows, tees, and couplers to create the desired arrangement. Ensure a slight angle for nutrient flow back to the reservoir.
  5. Install the nutrient delivery system: Connect the submersible pump to the tub or reservoir. Attach PVC pipes or hoses from the pump to the top end of the vertical growing tubes. This will allow the nutrient solution to flow down through the pipes and reach the plants’ roots.
  6. Add net pots and growing medium: Place net pots or cups into the holes drilled in the vertical pipes. Fill them with a suitable growing medium such as perlite, vermiculite, or coconut coir. Insert your plant seedlings or clones into the growing medium, ensuring the roots reach the nutrient solution.
  7. Set up the nutrient solution: Mix the appropriate hydroponic nutrient solution according to the manufacturer’s instructions. Fill the reservoir with the solution, making sure the pump is fully submerged.
  8. Optional: Incorporate an air pump and air stones into the reservoir to improve oxygenation of the nutrient solution. This can benefit the roots and overall plant health.
  9. Test the system: Turn on the pump and check the flow of the nutrient solution through the pipes. Adjust the pump’s flow rate if necessary to ensure proper irrigation and drainage.
  10. Maintain and monitor: Regularly check the pH and nutrient levels in the reservoir, making adjustments as needed. Monitor plant growth, and prune or trellis the cucumber vines as they grow.

Remember to research and understand the specific requirements of the plants you intend to grow. Hydroponic systems require proper monitoring, maintenance, and adjustment of environmental factors to ensure successful plant growth and development.