Ethephon Treatment Research Articles

EFFECT OF SOME GROWTH RETARDANTS ON GROWTH AND FLOWERING OF HELIANTHUS ANNUUS L. CV. SUNRICH ORANGE SUMMER 981V PLANTS A- EFFECT OF FOLIAR SPRAY TREATMENTS WITH ANCYMIDOL, DAMINOZIDE AND ETHEPHON

Pot experiments were carried out at the nursery of Hort. Res. Inst, Giza, Egypt throughout the two successive seasons of 2014 and 2015. The work embodied in this paper was to study the influence of some growth regulators (daminozide, ancymidol and ethephon) on sunflower (Helianthus annuus L. cv. Sunrich Orange Summer 981V) plant for achieving the hope of producing dwarf plant of good quality, suitable for using as a pot plant. Results indicated that most treatments reduced stem length of the treated plants with the superiority of 2450 ppm daminozide treatment which induced 50% reduction in such trait, compared to the control plants in the two seasons. However, stem diameter and number of internodes/stem were improved in response to all the used treatments. Internode length, stem fresh and dry weights were decreased with few exceptions, but the greatest decrease in these criteria was attained by daminozide treatment at any rate and ethephon one at 250 ppm. Number of leaves/plant were increased by the various treatments. Root length increased over control with few exceptions in both seasons. However, the highest averages in most measurements were achieved by ancymidol, especially at 20 ppm level. A significant flowering earliness in the two seasons was noticed in plants sprayed with ethephon at 250 ppm. The least number of days from flower bud appearance to opening was obtained by the 20 ppm ancymidol treatment, but the plants treated with the other treatments took longer time to anthesis. Ethephon treatments elevated the mean number of lateral buds/stem to the maximum, while ancymidol ones gave the largest flower heads. Number of ray flowers/head, disc diameter and flower head fresh and dry weights were improved due to most treatments. Content of photosynthetic pigments were slightly improved with few exceptions. Total phenols content reached the maximum by ancymidol treatments, followed by the ethephon ones. However, total indoles content was not affected by most of the used treatments. In addition, the percent of total soluble sugars was increased by ancymidol at 5 ppm, daminozide at 2450 ppm and ethephon at 500 ppm treatments, while other treatments declined it. On the other hand, the percent of N, P and K was generally decreased in response to the various treatments, with few exceptions as compared to control.

Ethephon As a Potential Abscission Agent for Table Grapes: Effects on Pre-Harvest Abscission, Fruit Quality, and Residue.

Some plant growth regulators, including ethephon, can stimulate abscission of mature grape berries. The stimulation of grape berry abscission reduces fruit detachment force (FDF) and promotes the development of a dry stem scar, both of which could facilitate the production of high quality stemless fresh-cut table grapes. The objective of this research was to determine how two potential abscission treatments, 1445 and 2890 mg/L ethephon, affected FDF, pre-harvest abscission, fruit quality, and ethephon residue of Thompson Seedless and Crimson Seedless grapes. Both ethephon treatments strongly induced abscission of Thompson Seedless berries causing >90% pre-harvest abscission. Lower ethephon rates, a shorter post-harvest interval, or berry retention systems such as nets, would be needed to prevent excessive pre-harvest losses. The treatments also slightly affected Thompson Seedless berry skin color, with treated fruit being darker, less uniform in color, and with a more yellow hue than non-treated fruit. Ethephon residues on Thompson Seedless grapes treated with the lower concentration of ethephon were below legal limits at harvest. Ethephon treatments also promoted abscission of Crimson Seedless berries, but pre-harvest abscission was much lower (≅49%) in Crimson Seedless compared to Thompson Seedless. Treated fruits were slightly darker than non-treated fruits, but ethephon did not affect SSC, acidity, or firmness of Crimson Seedless, and ethephon residues were below legal limits.

Onion Quality Affected by Ethanol and Ethephon During Storage

In the present study the effect of ethanol, a perception ethylene action suppresser and ethephon, an ethylene inducer (1 and 2 %) was studied as postharvest application on rabi 2012 (May harvest) produce at Directorate of Onion and Garlic Research, Pune. Two onion varieties of the region viz. Bhima Kiran (light red) and B. Shakti (dark red) were used being popularly grown. Top and bottom ventilated storage structure was used and data was recorded before storage and after 2 and 4 months of storage. Results revealed that B. Kiran had more storability than B. Shakti. After 4 months of storage, ethanol treatment (2 %) restricted weight loss to 19.09 % than 38.57 % (control) in B. Shakti and to 14.84 % than 23.81 % (control) in B. Kiran. It also reduced the sprouting significantly to 3.09 % as compared to 4.15 % (control) in B. Kiran and to 6.51 % as compared to 9.98 % (control) in B. Shakti. However, ethephon treatment (1 %) altered the postharvest losses up to 2 months only and effect was non-significant thereafter. Biochemical attributes varied significantly in both varieties. Total sugars and flavonoids decreased during storage irrespective of chemical treatment. Total proteins, total phenols and vitamin-C increased over the storage and were significantly altered due to postharvest applications.

Profiling Ethylene-Responsive Genes Expressed in the Latex of the Mature Virgin Rubber Trees Using cDNA Microarray.

Ethylene is commonly used as a latex stimulant of Hevea brasiliensis by application of ethephon (chloro-2-ethylphosphonic acid); however, the molecular mechanism by which ethylene increases latex production is not clear. To better understand the effects of ethylene stimulation on the laticiferous cells of rubber trees, a latex expressed sequence tag (EST)-based complementary DNA microarray containing 2,973 unique genes (probes) was first developed and used to analyze the gene expression changes in the latex of the mature virgin rubber trees after ethephon treatment at three different time-points: 8, 24 and 48 h. Transcript levels of 163 genes were significantly altered with fold-change values ≥ 2 or ≤ –2 (q-value < 0.05) in ethephon-treated rubber trees compared with control trees. Of the 163 genes, 92 were up-regulated and 71 down-regulated. The microarray results were further confirmed using real-time quantitative reverse transcript-PCR for 20 selected genes. The 163 ethylene-responsive genes were involved in several biological processes including organic substance metabolism, cellular metabolism, primary metabolism, biosynthetic process, cellular response to stimulus and stress. The presented data suggest that the laticifer water circulation, production and scavenging of reactive oxygen species, sugar metabolism, and assembly and depolymerization of the latex actin cytoskeleton might play important roles in ethylene-induced increase of latex production. The results may provide useful insights into understanding the molecular mechanism underlying the effect of ethylene on latex metabolism of H. brasiliensis.

Cloning and expression analysis of three genes encoding ubiquitins in papaya (Carica papaya L.)

ABSTRACTPapaya (Carica papaya L.) fruit have a short shelf-life due to rapid ripening induced by ethylene, which usually results in a high percentage of product loss. However, little is known about the genetic mechanism of ripening and the attributes of fruit quality. Ubiquitin (UBQ) proteins have received increasing attention because they play important roles in response to ripening and in regulating certain developmental processes in plants. In the present study, three genes encoding UBQ proteins, CpUBI1, CpUBI2, and CpUBI3, were isolated from papaya fruit. The lengths of the cDNAs of CpUBI1, CpUBI2, and CpUBI3 were 1,485 bp, 1,642 bp, and 529 bp, encoding 306, 308, and 156 predicted amino acids, respectively. Sequence analysis demonstrated that the CpUBI1 and CpUBI2 proteins contained four consecutive structural domains of the UBQ superfamily, while CpUBI3 contained a ribosomal domain structure of the S27a superfamily. RT-qPCR analysis demonstrated that ethephon treatment increased CpUBI gene expression significantly, compared to 1-methylcyclopropene (1-MCP) treatment and the untreated controls. Levels of CpUBI1 and CpUBI2 gene expression were significantly higher than CpUBI3. These results suggested that CpUBI1, CpUBI2, and CpUBI3 might have different roles during papaya fruit ripening and softening.

Influence of ethephon on ripening and quality of winter tomato fruit harvested at different maturity stages

An experiment taking tomato fruits (cv. BARI Tomato-14) of three maturity stages (mature green stage, breaker stage and half ripen stage) and four ethephon levels [control (distilled water spray), 500, 750 and 1000 ppm] was carried out at the laboratory of plant physiology section of Horticulture research centre, Bangladesh Agricultural Research Institute) during February 14, 2013 to February 27, 2012 to find out the suitable stage of fruit maturity for post harvest application of ethephon (ethrel) for tomato ripening. The source of ethrel was Spectrum (ethephon 39%) manufactured in the United States of America. Treatment with 500 - 1000 ppm ethephon hastened ripening of tomato by 4 days in mature green stage but by 2 and 4 days in breaker stage tomatoes when compared with control fruits. The highest value of rotting was shown by half ripen tomatoes. The 1000 ppm ethrel gave the maximum rotting irrespective of maturity stages. However, the maximum weight loss and shelf life were found in green mature tomatoes. The shelf life of tomato fruits of green mature and breaker stage tomatoes treated with 500 and 750 ppm was also high. The percentage of rotting and weight loss was increased with gradual advancement of time. The highest value of weight loss and shelf life was recorded in green mature tomatoes without ethephon and with 500 and 750 ppm ethephon treatment. The highest value of vitamin-C, TSS and titrable acidity were shown by half ripen and pH by green mature tomatoes at different days of storage. The ethephon concentration of 750 ppm the gave maximum vitamin-C at 6 and 9 days of storage but 1000 ppm gave the maximum TSS% followed by 750 ppm ethephon. The ethephon @ 750 ppm produced the maximum TSS at 9 day of storage in mature green tomatoes but in breaker and half ripen stage tomatoes 750 ppm ethephon gave TSS identical to 1000 ppm at different days of storage. The residue level of ethrel in tomato fruits treated with all ethephon concentrations at 3 and 5 days of storage was below 2 mg/kg which is safe for human health. Therefore, treated tomatoes should be consumed after 3 days of ethephon application.Bangladesh J. Agril. Res. 40(4): 567-580, December 2015

Defoliation responses of different grapevine cultivars to postharvest ethephon treatments

The defoliation responses of several grapevine cultivars to postharvest ethephon sprays at 0, 500, 2000, 5000 ppm were observed. Sprays were applied at the beginning of October to vines of Barbera, Carignane, Emerald Seedless, Ribier, Ruby Seedless, Thompson Seedless and Flame Tokay cultivars. The most effective concentration was 5000 ppm. The defoliation response varied greatly among the varieties. Barbera and Carignane were almost completely defoliated 20-30 d after treatment, whereas Flame Tokay showed no response. However, high concentrations of ethephon resulted in a considerable delay in shoot development the following spring. Defoliation induite en differents cepages par un traitement avec de l'ethephon apres la vendange La defoliation causee par des traitements d'ethephon (0, 500, 2000, 5000 ppm) a ete etudiee sur differents cepages (V. vinifera). Les applications ont ete faites le 10 octobre sur les cepages a raisin de table et de cuve ci-apres: Barbera, Carignane; Emerald Seedless, Ribier, Ruby Seedless, Thompson Seedless et Flame Tokay. La concentration de 5000 ppm se revela la plus efficace. La defoliation des plantes traitees a ete tres differente selon les cepages: Barbera et Carignane par exemple ont ete presque completement prives des feuilles apres 20-30 d du traitement, tandis que le Flame Tokay ne donna qu'une tres faible reponse. Il faut signaler en tout cas que les concentrations les plus fortes d'ethephon ont cause un retard considerable dans le debourrement du printemps suivant.

Efficient Breeder Seed Production Utilizing Ethephon to Promote Floral and Fruit Abscission in Ornamental Chile Peppers

Controlled abscission of floral structures is an important horticultural technique that has many applications throughout the growing season. A novel use of chemical abscission in chile pepper (Capsicum annuum) is the removal of open flowers and fruit for the production of breeder seed. For efficiency of abscising flower buds, open flowers, and fruit of ornamental chile peppers, two foliar spray treatment levels, 1000 and 2000 ppm ethephon were tested. Ornamental chile peppers were chosen because they are prolific flower and fruit producers, making removal of potentially cross-pollinated fruit and open flowers laborious. Flower bud and flower number were reduced with both 1000- and 2000-ppm ethephon treatments, while fruit number decreased only with 2000-ppm ethephon treatment. ‘NuMex Easter’ was more sensitive to ethephon treatment as compared with ‘Chilly Chili’ and ‘Riot’. Ethephon had no negative impacts on end of the season growth index, mature fruit number, and seed number. We found ethephon can reduce numbers of flower buds, open flowers, and fruit with no long-term effect on mature fruit and seed number, making it a useful tool for the production of breeder seed in chile pepper breeding programs.

Effects of Ethephon on Terpenoids in Cannabis sativa L. in Vegetative Stage

In the present study we investigated the effect of ethephon on changes in the amount of many terpenoid compounds including, tetrahydrocannabinol (THC), cannabidiol (CBD), chlorophyll, carotenoids, α-tocopherol and pyruvate as one of substrate in plastidic terpenoids biosynthesis in Cannabis sativa at vegetative stage. Treatment with 1 and 100 µM ethephon increased THC content up to 9 fold in vegetative stage. Plants treated with 10 µM ethephon had more CBD content in comparison with control plants. The amount of CBD decreased in plants subjected to 5 and 100 µM ethephon. Leave area in plant treated with ethephon did not show significant changes in comparison to control plants. Ethephon treatment caused a declined in the amount of α-tocopherol. The levels of chlorophylls and carotenoids raised in treated plants with 1 µM ethephon. With regard to the fact that ethephon had not negative effect on the surface of leaves and chlorophyll content thus its application can be a suitable way for increasing of THC and α-tocopherol in Cannabis sativa L.

ETHEPHON SPRAYS AS A DEFOLIANT IN ‘NIAGARA ROSADA’ VINE SUBJECTED TO TWO CROP PRODUCTION PER YEAR

ABSTRACT In climate region Cwa of the State of São Paulo the technique of double cropping the grapevine is possible, however, when it is time for the second pruning of the crop, most of the vine’s leaves are still in the plant, posing the problem that the use of ethephon as a defoliant could increase leaf senescence and improve the vine management. The objective of this study was to evaluate the effects of ethephon spray as a defoliant in the development and production of the ‘Niagara Rosada’ vine when subjected to double cropping, and the influence this bioactivator may have on carbohydrate reserves in the branch. The experiments were conducted in a commercial, non-irrigated area in agricultural years of 2011/2012 and 2012/2013. The length, diameter and total carbohydrate reserves of the branches, as well as bud break, number of clusters, crop production, length, width and mass of cluster, berry diameter, soluble solids and titratable acidity were evaluated. Ethephon treatments were applied at a concentration of 1,440 mg L-1 and 2,160 mg L-1 at 20 and 15 days before pruning. As a control, the vines were defoliated by hand at the time of pruning. A randomized block experimental design was used. Data was subjected to analysis of variance and means were compared by the Tukey test at 5% significance level. In conclusion, we propose that ethephon sprays promoted vine defoliation and improved the bud break, altered plant development and crop production. This was not due to increases in concentration of carbohydrate reserves in the branches, but due to a higher induction stimulus of bud break, which allowed the vines to express their higher yield capacity.

Characterization of the Pear (Pyrus ussuriensis) Actin-depolymerizing Factor PuADF During Fruit Ripening

The polymerization or depolymerization of the cytoskeleton is very important in various aspects of plant development. ADF (actin-depolymerizing factor) is a typical actin binding protein that can mediate the polymerization or depolymerization of the actin cytoskeleton, but its role in fruit ripening remains unclear. Here, we characterized an ADF gene, PuADF. The expression of PuADF was evaluated in young leaves, stems, flowers, and roots as well as in fruits. The expression of PuADF was induced by ethephon treatment but inhibited by 1-MCP treatment. To explore the network of PuADF function in ‘Nanguo’ pear fruits ripening, we screened a cDNA library from ‘Nanguo’ pear fruits using PuADF as bait. Two potential interactors of PuADF were identified, PuAS (Asparagine Synthetase) and PuDAD1 (Defender Against Death 1), both of which have been associated with PCD (Programmed Cell Death). This direct interaction was further confirmed by yeast two-hybrid analyses. The expression levels of PuAS and PuDAD1 were affected by ethylene. Our results indicated that PuADF is involved in ethylene-mediated fruit ripening and might be related to PCD during fruit ripening. The possible mechanisms are discussed.

Analysis of differential expression of genes induced by ethephon in elongating internodes of maize plants

Plant growth regulators (PGRs) are commonly used in cereal cropping systems to restrict plant height and control lodging. Ethephon has been reported to shorten internodes and increase grain yield of maize. To analyze the transcriptomic profiles of maize internode elongation following ethephon treatment, differentially expressed genes were compared between the treatment and control samples of inbred line Zong 31 using the Affymetrix Maize Genome Array. According to the microarray data, 326 probe sets showed significant change in expression. Further research revealed that the most remarkable effects of ethephon on maize internodes elongation occurred during a 48 h period, when 89 differentially expressed genes were detected. There were dramatic change in transcript levels at 24 h and six Auxin transport genes and four gibberellin biosynthesis pathway genes were differ- entially expressed in Zong 31 in response to ethephon treatment. In summary, we showed that gaseous ethylene release is involved in internode meristem cell elongation through the regulation of plant hormone signaling in maize. This work provides a platform for studies in which candidate genes will be functionally tested for involve- ment in internode elongation.

Influence of ethephon treatments on quality changes in dashehari mango (Mangifera indica L.) during ripening

Influence of Ethephon Treatments on Quality Changes in Dashehari Mango (Mangifera indica L.) during Ripening Mango fruits require ripening treatment after harvest to hasten ripening and develop ideal eating quality. Present investigations were carried out to elucidate the potential of ethephon as postharvest dip treatment for enhancement of ripening and quality characteristics of ‘Dashehari’ mango fruits. Freshly harvested fruits were immersed in aqueous solutions of ethephon at 0, 200, 400, 600 or 800 µLL-1 and then placed at ambient temperature for ripening studies. Evaluation of physico-chemical parameters was made at 0 (before treatment), 48, 72, 96, 120 and 144 hrs of ripening. Pulp colour was expressed as L*, a*, b*, h0 and C* values. Results indicated that fruit firmness declined linearly to the dose of ethephon applied and fruit texture became edible after 72 hrs in ethephon 600 or 800 µLL-1treatments. Total soluble solids increased with ripening of fruits and maximum values were recorded at the end of ripening period. There was consistent decrease in juice acid content of fruits with ethephon applications. Highest dose of ethephon (800µLL-1) induced ripening in fruits after 72 hrs of treatment but showed detrimental effect on sensory quality afterwards. However, fruits given 600 µLL-1 ethephon dip ripened after 72 hrs after treatments and these fruit maintained excellent quality attributes up to 144 hrs. Ethephon applications exhibited enhancement in colour attributes of fruit pulp in terms of improved redness or yellowness and chroma. The results indicated that dipping mango fruits in 600 µLL-1 ethephon developed the superior ripening quality at ambient temperature...

Genome-wide identification of rubber tree (Hevea brasiliensis Muell. Arg.) aquaporin genes and their response to ethephon stimulation in the laticifer, a rubber-producing tissue.

BackgroundNatural rubber, an important industrial raw material, is specifically synthesized in laticifers located inside the rubber tree (Hevea brasiliensis Muell. Arg.) trunk. Due to the absence of plasmodesmata, the laticifer water balance is mediated by aquaporins (AQPs). However, to date, the characterization of H. brasiliensis AQPs (HbAQPs) is still in its infancy.ResultsIn this study, 51 full-length AQP genes were identified from the rubber tree genome. The phylogenetic analysis assigned these AQPs to five subfamilies, including 15 plasma membrane intrinsic proteins (PIPs), 17 tonoplast intrinsic proteins (TIPs), 9 NOD26-like intrinsic proteins (NIPs), 4 small basic intrinsic proteins (SIPs) and 6 X intrinsic proteins (XIPs). Functional prediction based on the analysis of the aromatic/arginine (ar/R) selectivity filter, Froger’s positions and specificity-determining positions (SDPs) showed a remarkable difference in substrate specificity among subfamilies. Homology analysis supported the expression of 44 HbAQP genes in at least one of the examined tissues. Furthermore, deep sequencing of the laticifer transcriptome in the form of latex revealed a key role of several PIP subfamily members in the laticifer water balance, and qRT-PCR analysis showed diverse expression patterns of laticifer-expressed HbAQP genes upon ethephon treatment, a widely-used practice for the stimulation of latex yield.ConclusionsThis study provides an important genetic resource of HbAQP genes, which will be useful to improve the water use efficiency and latex yield of Hevea.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-015-2152-6) contains supplementary material, which is available to authorized users.

Ethephon induced abscission in mango: physiological fruitlet responses.

Fruitlet abscission of mango is typically very severe, causing considerable production losses worldwide. Consequently, a detailed physiological and molecular characterization of fruitlet abscission in mango is required to describe the onset and time-dependent course of this process. To identify the underlying key mechanisms of abscission, ethephon, an ethylene releasing substance, was applied at two concentrations (600 and 7200 ppm) during the midseason drop stage of mango. The abscission process is triggered by ethylene diffusing to the abscission zone where it binds to specific receptors and thereby activating several key physiological responses at the cellular level. The treatments reduced significantly the capacity of polar auxin transport through the pedicel at 1 day after treatment and thereafter when compared to untreated pedicels. The transcript levels of the ethylene receptor genes MiETR1 and MiERS1 were significantly upregulated in the pedicel and pericarp at 1, 2, and 3 days after the ethephon application with 7200 ppm, except for MiETR1 in the pedicel, when compared to untreated fruitlet. In contrast, ethephon applications with 600 ppm did not affect expression levels of MiETR1 in the pedicel and of MiERS1 in the pericarp; however, MiETR1 in the pericarp at day 2 and MiERS1 in the pedicel at days 2 and 3 were significantly upregulated over the controls. Moreover, two novel short versions of the MiERS1 were identified and detected more often in the pedicel of treated than untreated fruitlets at all sampling times. Sucrose concentration in the fruitlet pericarp was significantly reduced to the control at 2 days after both ethephon treatments. In conclusion, it is postulated that the ethephon-induced abscission process commences with a reduction of the polar auxin transport capacity in the pedicel, followed by an upregulation of ethylene receptors and finally a decrease of the sucrose concentration in the fruitlets.

Endogenous ethylene regulates accumulation of α- and β-carotene in the pulp of harvested durian fruit

Durian (Durio zibethinus Murr.) cv. Chanee fruits were harvested at commercial maturity and stored at 25°C for 9 days. Respiration rates and ethylene production increased during storage, while pulp firmness decreased. The concentrations of the two main pulp carotenoids (α- carotene and β-carotene) increased by more than 30% during storage. The minor carotenoids zeaxanthin also increased, while an increase in lutein was not statistically different from controls. Treatment at 25°C with 500μLL−1 1-methylcyclopropene (1-MCP) for 12h delayed the increase in respiration rate and in ethylene production. It also resulted in a later decrease in pulp firmness. 1-MCP largely prevented the increase in pulp carotenoid concentrations. Ethephon treatment (brushing the stem cut surface) increased the measured ethylene and slightly hastened the decrease in pulp firmness, but did not measurably affect the respiration and carotenoid concentrations. It is concluded that the postharvest increase in pulp α-carotene and β-carotene concentrations is an integral part of pulp ripening in this cultivar.

Exogenous phytohormones increase the accumulation of health-promoting metabolites, and influence the expression patterns of biosynthesis related genes and biological activity in Chinese cabbage (Brassica rapa spp. pekinensis)

The effects of jasmonic acid (JA), salicylic acid (SA), abscisic acid (ABA) and ethephon (ETH) on glucosinolate (GSL), carotenoid, chlorophyll, anthocyanin and polyphenolic contents, and the gene regulation of biosynthesis and biological activities were investigated in Chinese cabbage (Brassica rapa spp. pekinensis) plants. JA, SA, ABA and ETH significantly increased indole, aliphatic and aromatic GSL contents. Individual phenols, total polyphenols and biological activities substantially increased in JA, SA, ABA and ETH treated plants. Lutein and β-carotene contents were higher after ABA and SA treatment. Total chlorophyll and carotenoid contents considerably increased after ABA treatment and anthocyanin content increased after JA, SA, ABA, and ETH treatment. Plants treated with exogenous JA, SA, ABA and ETH showed significant increases in the expression of genes related to phytochemical production. These results demonstrated that JA, SA, ABA, and ETH significantly increased phytochemical contents and enhanced biological activity in Chinese cabbage plants.

Genome-wide digital transcript analysis of putative fruitlet abscission related genes regulated by ethephon in litchi.

The high level of physiological fruitlet abscission in litchi (Litchi chinensis Sonn.) causes severe yield loss. Cell separation occurs at the fruit abscission zone (FAZ) and can be triggered by ethylene. However, a deep knowledge of the molecular events occurring in the FAZ is still unknown. Here, genome-wide digital transcript abundance (DTA) analysis of putative fruit abscission related genes regulated by ethephon in litchi were studied. More than 81 million high quality reads from seven ethephon treated and untreated control libraries were obtained by high-throughput sequencing. Through DTA profile analysis in combination with Gene Ontology and KEGG pathway enrichment analyses, a total of 2730 statistically significant candidate genes were involved in the ethephon-promoted litchi fruitlet abscission. Of these, there were 1867 early-responsive genes whose expressions were up- or down-regulated from 0 to 1 d after treatment. The most affected genes included those related to ethylene biosynthesis and signaling, auxin transport and signaling, transcription factors (TFs), protein ubiquitination, ROS response, calcium signal transduction, and cell wall modification. These genes could be clustered into four groups and 13 subgroups according to their similar expression patterns. qRT-PCR displayed the expression pattern of 41 selected candidate genes, which proved the accuracy of our DTA data. Ethephon treatment significantly increased fruit abscission and ethylene production of fruitlet. The possible molecular events to control the ethephon-promoted litchi fruitlet abscission were prompted out. The increased ethylene evolution in fruitlet would suppress the synthesis and polar transport of auxin and trigger abscission signaling. To the best of our knowledge, it is the first time to monitor the gene expression profile occurring in the FAZ-enriched pedicel during litchi fruit abscission induced by ethephon on the genome-wide level. This study will contribute to a better understanding for the molecular regulatory mechanism of fruit abscission in litchi.

A preharvest treatment of ethephon and methyl jasmonate affects mechanical harvesting performance and composition of 'Verdejo' grapes and wines

A preharvest treatment of ethephon and methyl jasmonate affects mechanical harvesting performance and composition of 'Verdejo' grapes and wines

Effect of Ethephon and Nitrogen Fertilizer on Nitrogen Uptake, Nitrogen Use Efficiency and Yield of Summer Maize

A field experiment using maize hybrid Zhengdan 958 was conducted to study effect of ethephon (0 and 180 g ha) and nitrogen fertilizer (0, 75, 150, and 225 kg N ha) on summer maize yield and yield components, nitrogen uptake, nitrogen use and SPAD value. The results showed that ethephon significantly decreased nitrogen uptake and N uptake efficiency, whereas markedly increased N utilization efficiency. N agronomic efficiency under ethephon treatment was 32.7%–34.6% more than that under control, and ethephon had no negative effect on maize yield and yield components. With increase nitrogen fertilizer of application, maize yield, yield components and nitrogen uptake were increased, but N uptake efficiency, N utilization efficiency, N partial factor productivity and N agronomic efficiency were decreased. Nitrogen uptake under 225 kg N ha treatment was 68.4%–91.8% more than that under 0 kg N ha. However there was no difference for nitrogen uptake between 225 kg N ha and 150 kg N ha treatments. Significant effect of ethephon × nitrogen was observed on nitrogen uptake, N uptake efficiency and N agronomic efficiency. Ethephon as well as higher nitrogen rate increased SPAD value of ear leaf during grain filling stage, while there was no significant interaction between ethephon and nitrogen fertilizer on SPAD value. Correlation analysis indicated that summer maize yield was significantly positively correlated with nitrogen uptake at silking stage and harvest stage and with SPAD value of ear leaf.