Effect Of Methyl Jasmonate Research Articles

Effect of Methyl Jasmonate on the Terpene Trilactones, Flavonoids, and Phenolic Acids in Ginkgo biloba L. Leaves: Relevance to Leaf Senescence

The present study compared the effects of natural senescence and methyl jasmonate (JA-Me) treatment on the levels of terpene trilactones (TTLs; ginkgolides and bilobalide), phenolic acids, and flavonoids in the primary organs of Ginkgo biloba leaves, leaf blades, and petioles. Levels of the major TTLs, ginkgolides B and C, were significantly higher in the leaf blades of naturally senesced yellow leaves harvested on 20 October compared with green leaves harvested on 9 September. In petioles, a similar effect was found, although the levels of these compounds were almost half as high. These facts indicate the importance of the senescence process on TTL accumulation. Some flavonoids and phenolic acids also showed changes in content related to maturation or senescence. Generally, the application of JA-Me slightly but substantially increased the levels of TTLs in leaf blades irrespective of the difference in its application side on the leaves. Of the flavonoids analyzed, levels of quercetin, rutin, quercetin-4-glucoside, apigenin, and luteolin were dependent on the JA-Me application site, whereas levels of (+) catechin and (−) epicatechin were not. Application of JA-Me increased ferulic acid and p-coumaric acid esters in the petiole but decreased the levels of these compounds in the leaf blade. The content of p-coumaric acid glycosides and caffeic acid esters was only slightly modified by JA-Me. In general, JA-Me application affected leaf senescence by modifying the accumulation of ginkogolides, flavonoids, and phenolic acids. These effects were also found to be different in leaf blades and petioles. Based on JA-Me- and aging-related metabolic changes in endogenous levels of the secondary metabolites in G. biloba leaves, we discussed the results of study in the context of basic research and possible practical application.

The roles of SlMYC2 in regulating ascorbate-glutathione cycle mediated by methyl jasmonate in postharvest tomato fruits under cold stress

This study parsed the mechanism of SlMYC2 involving methyl jasmonate (MeJA)-mediated tomato fruit chilling tolerance. The data indicated that the application of MeJA significantly prevented chilling injury (CI) and inhibited the accumulation of hydrogen peroxide (H2O2) and superoxide anions (O2•−) in tomato fruit during cold storage. The accumulation of endogenous ascorbate (AsA) and glutathione (GSH) contents in fruit were enhanced by MeJA treatment resulting from increasing activities of enzymes related to AsA-GSH cycle. Meanwhile, the MeJA-treated fruit exhibited significantly higher expression levels of C-repeat-binding factor 1 (SlCBF1), cold regulated gene (SlCOR413) and inducer of SlCBF expression (SlICE1 and SlICEa), which belong to the SlICE-SlCBF-SlCOR (ICC) signaling pathway. However, the effects of MeJA were inhibited by the silence of SlMYC2. The expression levels of SlCBF1, SlCOR413, SlICE1 and SlICEa were reduced in SlMYC2-silenced fruits, and there was no significant difference in CI index and the indexes related to AsA-GSH cycle between (SlMYC2-silenced+MeJA)-treated fruit and control during most storage periods. In addition, correlation analysis indicated that the indexes involved in AsA-GSH cycle and ICC signaling pathway were closely related to the transcription of SlMYC2. Therefore, these results illustrated that SlMYC2 was involved in the regulation of ASA-GSH cycle and ICC signaling pathway mediated by MeJA during the cold tolerance of tomato fruit.

Metil Jasmonat ve Modifiye Atmosfer Paketleme Uygulamalarının Soğukta Muhafaza Süresince Kayısı Meyvesinin Fiziksel ve Mekanik Özelliklerine Etkileri

In this study, the effects of methyl jasmonate [MeJA (0.5 and 1.0 mmol L-1)] and modified atmosphere packaging (MAP) applications on the physical and mechanical properties of ‘Precoce de Thyrinthe’ apricot variety during cold storage were investigated. Fruit were stored at 0±0.5C and 90±5% relative humidity for 20 days. Physical properties of apricot such as geometric mean diameter, sphericity, surface area, bulk and fruit densities; mechanical properties such as puncture-compression forces and friction coefficient were determined. It was observed that MeJA application did not produce a significant difference on the size characteristics of apricot compared to the harvest period. Regarding the storage time, decreases were observed in the change of compression force results obtained from the X-, Y- and Z- axes according to the increase in the storage time. Effect on the puncture force on three axes showed a lower tendency to decrease in MAP application than in the harvest period compared to the application without MAP. The coefficient of friction on laminate and galvanized sheet surfaces was lower than PVC, plywood and rubber surfaces.

Effect of methyl jasmonate and salicylic acid on antioxidant activity, phenolic and flavonoid compounds in Nigella sativa cell culture

هدف: هدف این مطالعه القای کالوس و تولید سوسپانسیون سلولی از گیاه دارویی شناخته شده سیاه‌دانه Nigella sativa)) و به‌دنبال آن تاثیر الیسیتورهای سالیسیلیک­اسید و متیل­جاسمونات برروی مقدار و توان آنتی اکسیدانت­های آن بود.مواد و روش‏ها: از برگ­های لپه­ای گیاه، کالوس تهیه شد. سپس استقرار کشت سوسپانسیون سلولی با استفاده از کالوس مناسب، انجام شد. سلول­ها تحت تیمار با الیسیتورهای سالیسیلیک­اسید و متیل­جاسمونات قرار گرفتند و محتوی فنل کل و کارتنوئیدها در آن­ها سنجش شد. توان آنتی­اکسیدانتی باروش FRAP اندازه­گیری شد.نتایج: نتایج نشان داد که تیمارها تاثیر معنی­داری بر وزن­تر کالوس ندارند اما وزن خشک کالوس تیمار­شده با سالیسیلیک­اسید به‌طور معنی­داری کاهش می­یابد. بیش‌ترین مقدار محتوی فنل کل در کشت کالوس و سوسپانسیون سلولی در تیمار با سالیسیلیک­­اسید مشاهده شد. تیمار سوسپانسیون سلولی با هر دو الیسیتور باعث افزایش معنی­دار مقدار فلاونوئیدها شد. توان آنتی­اکسیدانتی سوسپانسیون سلولی نیز در تیمارها افزایش معنی­داری یافت که این افزایش در تیمار متیل­جاسمونات کم‌تر بود.نتیجه‏گیری: باتوجه به‌نتایج به‌دست آمده به‌نظر می­رسد الیسیتور سالیسیلیک­اسید در سوسپانسیون سلولی سیاه‌دانه باعث القای بیش‌تر پاسخ نسبت به الیسیتور متیل­جاسمونات شده و در نتیجه باعث القای بیش‌تر خاصیت آنتی­اکسیدانتی می­شود.

Methyl jasmonate effects on sugarbeet root responses to postharvest dehydration.

BackgroundSugarbeet (Beta vulgaris L.) roots are stored under conditions that cause roots to dehydrate, which increases postharvest losses. Although exogenous jasmonate applications can reduce drought stress in intact plants, their ability to alleviate the effects of dehydration in postharvest sugarbeet roots or other stored plant products is unknown. Research was conducted to determine whether jasmonate treatment could mitigate physiological responses to dehydration in postharvest sugarbeet roots.MethodsFreshly harvested sugarbeet roots were treated with 10 µM methyl jasmonate (MeJA) or water and stored under dehydrating and non-dehydrating storage conditions. Changes in fresh weight, respiration rate, wound healing, leaf regrowth, and proline metabolism of treated roots were investigated throughout eight weeks in storage.ResultsDehydrating storage conditions increased root weight loss, respiration rate, and proline accumulation and prevented leaf regrowth from the root crown. Under dehydrating conditions, MeJA treatment reduced root respiration rate, but only in severely dehydrated roots. MeJA treatment also hastened wound-healing, but only in the late stages of barrier formation. MeJA treatment did not impact root weight loss or proline accumulation under dehydrating conditions or leaf regrowth under non-dehydrating conditions. Both dehydration and MeJA treatment affected expression of genes involved in proline metabolism. In dehydrated roots, proline dehydrogenase expression declined 340-fold, suggesting that dehydration-induced proline accumulation was governed by reducing proline degradation. MeJA treatment altered proline biosynthetic and catabolic gene expression, with greatest effect in non-dehydrated roots. Overall, MeJA treatment alleviated physiological manifestations of dehydration stress in stored roots, although the beneficial effects were small. Postharvest jasmonate applications, therefore, are unlikely to significantly reduce dehydration-related storage losses in sugarbeet roots.

Calcium and methyl jasmonate cross-talk in the secondary metabolism of grape cells

In grape cell cultures cv. Gamay Fréaux var. Teinturier, Ca was shown to decrease cell pigmentation through the inhibition of anthocyanin biosynthesis, while stimulating stilbenoids accumulation. Because methyl jasmonate (MeJA) is a well-known inducer of secondary metabolism in grape cells, and Ca antagonizes its stimulatory effect over several enzymes of core metabolic branches, in the present study we hypothesized that Ca and MeJA signaling pathways interact to regulate specific secondary metabolism routes. Grape cultured cells were elicited with MeJA or with MeJA + Ca and an UPLC-MS-based targeted metabolomic method was implemented to characterize their polyphenolic profiles. Results were compared with the profile of cells elicited with Ca only, previously reported. Data was complemented with gene expression analysis, allowing the assembly of a metabolic map that unraveled routes specifically regulated by both elicitors. MeJA + Ca specifically boosted E-resveratrol and E-ε-viniferin levels by 180% and 140%, respectively, in comparison to cells treated with MeJA only, while the stimulatory effect of MeJA over flavonoid synthesis was inhibited by Ca. In parallel, Ca downregulated most flavonoid pathway genes, including LAR1, ANS, BAN and ANR. Ca was able to mimic or potentiate the effect of MeJA on the expression of JA signaling genes, including JAR1, PIN and PR10. Transcript/metabolite correlation networks exposed the central influence of FLS1,STS,CDPK17 and COI1 in polyphenolic biosynthetic routes. This study highlights the potential of the MeJA-Ca combination for diverting polyphenolic metabolism towards the production of specific metabolites of interest, highly relevant in a biotechnological perspective.

Methyl jasmonate effects on pomegranate fruit yield and quality at harvest and during storage depend on the applied concentration

Methyl jasmonate effects on pomegranate fruit yield and quality at harvest and during storage depend on the applied concentration

Synergistic Effect of Methyl Jasmonate and Abscisic Acid Co-Treatment on Avenanthramide Production in Germinating Oats.

The oat (Avena sativa L.) is a grain of the Poaceae grass family and contains many powerful anti-oxidants, including avenanthramides as phenolic alkaloids with anti-inflammatory, anti-oxidant, anti-itch, anti-irritant, and anti-atherogenic activities. Here, the treatment of germinating oats with methyl jasmonate (MeJA) or abscisic acid (ABA) resulted in 2.5-fold (582.9 mg/kg FW) and 2.8-fold (642.9 mg/kg FW) increase in avenanthramide content, respectively, relative to untreated controls (232.6 mg/kg FW). Moreover, MeJA and ABA co-treatment synergistically increased avenanthramide production in germinating oats to 1505 mg/kg FW. Individual or combined MeJA and ABA treatment increased the expression of genes encoding key catalytic enzymes in the avenanthramide-biosynthesis pathway, including hydroxycinnamoyl-CoA:hydrocyanthranilate N-hydroxycinnamoyl transferase (HHT). Further analyses showed that six AsHHT genes were effectively upregulated by MeJA or ABA treatment, especially AsHHT4 for MeJA and AsHHT5 for ABA, thereby enhancing the production of all three avenanthramides in germinating oats. Specifically, AsHHT5 exhibited the highest expression following MeJA and ABA co-treatment, indicating that AsHHT5 played a more crucial role in avenanthramide biosynthesis in response to MeJA and ABA co-treatment of germinating oats. These findings suggest that elicitor-mediated metabolite farming using MeJA and ABA could be a valuable method for avenanthramide production in germinating oats.

Synergistic Effect of Methyl Jasmonate and Abscisic Acid Co-treatment on Avenanthramide Production in Germinating Oats

Synergistic Effect of Methyl Jasmonate and Abscisic Acid Co-treatment on Avenanthramide Production in Germinating Oats

Effects of methyl jasmonate on quality properties and phytochemical compounds of kiwifruit (Actinidiadeliciosa cv. ‘Hayward’) during cold storage and shelf life

The research aimed to assess the effects of methyl jasmonate (0.25, 0.5, and 1.0 mM MeJA) on weight loss and phytochemical compounds of kiwifruit (Actinidia deliciosa cv. `Hayward') throughout the cold storage and shelf life. Kiwifruits were stored at 0 ± 0.5 °C and 90 ± 5% RH for 180 days, and at 20 ± 1.0 °C and 80 ± 5% RH for 5 days in shelf life conditions. During cold storage, weight loss was significantly lower (P < 0.05) in 0.25 and 1.0 mM MeJA treatments than those of control and 0.5 mM MeJA treatments. The highest flesh firmness was determined in MeJA-treated fruits. In the latest measurement period of cold storage and shelf life, the lowest respiration rate was obtained from 0.5 and 1.0 mM MeJA treatments. MeJA-treated fruits had significantly higher hue angle at the end of cold storage. Generally, in shelf life analysis, acidity of MeJA-treated fruits was significantly lower than that of control fruits. At the end of cold storage, the highest vitamin C, total flavonoids, and antioxidant activity (DPPH) were measured in 1.0 mM MeJA treatment, whereas the highest total phenolics were detected in 0.25 mM MeJA treatment. Present findings revealed that MeJA could be used as an effective postharvest tool to maintain flesh firmness and phytochemical compounds of kiwifruits.

Methyl jasmonate application and flowering stage affect scent emission of Styrax japonicus

AbstractStyrax japonicus is a gorgeous species with high medicinal and ornamental values. Floral scent is an important feature of this species. However, the previous study on its floral scent is limited. To demonstrate the effects of methyl jasmonate on floral scent compounds in Styrax japonicus at different flowering stages, static headspace solid‐phase microextraction coupled with gas chromatography‐mass spectrometry was adopted. The results showed that 22 volatile compounds were identified in control at initial flowering, full flowering and end flowering stage. Besides, the relative content of these compounds increased with the development of flowers. Linalool, estragole and germacrene‐d were main volatiles. Compared to the control, 4 new compounds were determined under methyl jasmonate treatment, including β‐elemene, α‐muurolene, β‐caryophyllene and alloaromadendrene. 26 volatile compounds were found under 200 μmol/L methyl jasmonate treatment with much higher contents of α‐pinene and linalool. Meanwhile, 200 μmol/L methyl jasmonate enhanced the relative content of volatile compounds at three flowering stages. This treatment also contributed to the highest content of linalool, followed by control. The linalool content displayed a continuous increasement in both 200 μmol/L methyl jasmonate treatment and control. Our research highlighted that the application of methyl jasmonate, especially with the concentration of 200 μmol/L, had a more positive impact on the type and the relative content of volatile compounds in S japonicus flowers. The results helped to understand the release patterns of volatile compounds in S japonicus flowers and provide important information to regulate the floral scents.

Transcriptome sequencing revealed the mechanism of promoting floret opening by exogenous methyl jasmonate in sorghum.

The online version contains supplementary material available at 10.1007/s13205-021-02743-6.

Activation of L-type calcium channels and attenuation of oxidative stress are involved in the improving effect of methyl jasmonate on learning and memory and its anxiolytic property in rats.

The present study was designed to evaluate the effect of plant bioactive compound methyl jasmonate on learning and memory, anxiety-like behaviors, and brain oxidative stress in rats. It has been indicated that methyl jasmonate stimulates calcium-binding protein expression and increases intracellular calcium (Ca2+). Therefore, we investigated the potential role of L-type calcium channel on methyl jasmonate effects. The animals were intracerebroventriculary (i.c.v.) injected with different doses of methyl jasmonate (0.5, 2.5, and 5 µg/rat). L-type calcium channel blocker (nifedipine 5 µg/rat, i.c.v.) was injected 30 min before methyl jasmonate (5 µg/rat). Shuttle box apparatus was used to evaluate passive avoidance memory. Anxiety-like behaviors were assessed by open field and elevated plus maze tests. Lastly, oxidative stress-related indices were assessed in hippocampus and prefrontal cortex. The data showed that methyl jasmonate dose-dependently could improve passive avoidance learning and memory and reduce anxiogenic behaviors. The methyl jasmonate effects were significantly prevented by nifedipine. Furthermore, central microinjection of methyl jasmonate significantly decreased hydrogen peroxide concentration, and increased reactive oxygen species scavenger activity (catalase and peroxide enzymes) in rats' hippocampus as well as prefrontal cortex. Indeed, the results indicated that the beneficial effects of methyl jasmonate on learning and memory and anxiety might be partly associated with L-type calcium channel and partly on the inhibition of oxidant indices.

Methyl Jasmonate and Methyl-β-Cyclodextrin Individually Boost Triterpenoid Biosynthesis in Chlamydomonas Reinhardtii UVM4.

The commercialisation of valuable plant triterpenoids faces major challenges, including low abundance in natural hosts and costly downstream purification procedures. Endeavours to produce these compounds at industrial scale using microbial systems are gaining attention. Here, we report on a strategy to enrich the biomass of the biotechnologically-relevant Chlamydomonas reinhardtii strain UVM4 with valuable triterpenes, such as squalene and (S)-2,3-epoxysqualene. C. reinhardtii UVM4 was subjected to the elicitor compounds methyl jasmonate (MeJA) and methyl-β-cyclodextrine (MβCD) to increase triterpene yields. MeJA treatment triggered oxidative stress, arrested growth, and altered the photosynthetic activity of the cells, while increasing squalene, (S)-2,3-epoxysqualene, and cycloartenol contents. Applying MβCD to cultures of C. reinhardtii lead to the sequestration of the two main sterols (ergosterol and 7-dehydroporiferasterol) into the growth medium and the intracellular accumulation of the intermediate cycloartenol, without compromising cell growth. When MβCD was applied in combination with MeJA, it counteracted the negative effects of MeJA on cell growth and physiology, but no synergistic effect on triterpene yield was observed. Together, our findings provide strategies for the triterpene enrichment of microalgal biomass and medium.

Improving the quantitative and qualitative of Manfalouty pomegranate cultivar

Abstract One of the major physiological disorders for pomegranate cultivation is the excessive of fruit cracking. lately, a pomegranate physiological syndrome called ‘aril paleness’ in which a part or all of the arils appear discoloration, affect the quality of fruit and such fruits are not desired for consumer. The present research designed to evaluate the effects of methyl jasmonate (MJ), humic acid (HA) and potassium (K) on reducing these disorders and improving fruit quality. Seven treatments including MJ (5 and 10 ppm), HA (50 and 100 ppm), Liquid K (1 and 2%) and control, were tested on pomegranate trees spraying three times, at the beginning of flowering (during April), after full bloom (end of June) and before harvesting (mid-September), during the two seasons of study. Different parameters including yield, fruit cracking and fruit quality were measured. The obtained results indicated that spraying HA at 100 ppm and MJ at 10 ppm are considered the best in their effects on the yield components, fruit quality and anthocyanin content, however for decreasing the fruit cracking, it could be recommended to spray the fruits with K at 1% or MJ 10 ppm compared to the rest of the treatments.

Methyl jasmonate promotes wound healing by activation of phenylpropanoid metabolism in harvested kiwifruit

A rapid wound healing in vegetables and fruit is instrumental in maintaining fruit quality and extension of shelf life. In this study, wounded kiwifruit were separately treated with methyl jasmonate (MeJA) and diethyldithiocarbamic acid (DIECA, an inhibitor of jasmonate biosynthesis) to evaluate the effect of MeJA on wound healing of kiwifruit. The results showed that MeJA treatment leads to increases of endogenous JA biosynthesis, lipoxygenase (LOX) and 12-oxo-phytodienoic acid reductase (OPR) activities, and JA synthesis genes expression, while DIECA represses these processes. Meanwhile, MeJA promoted the autofluorescence of suberin polyphenolic (SPP) and the accumulation of SPP monomers. MeJA-treated group demonstrated significantly enhanced total phenols, flavonoids, and lignin contents. Besides, MeJA promoted the activities of phenylalanine ammonia-lyase (PAL), cinnamic acid-4-hydroxylase (C4H), 4-COumaric-COA ligase (4CL), peroxidase (POD), polyphenol oxidase (PPO), and the respective gene expression levels. Results suggest that wound healing in kiwifruit could be promoted by MeJA via activation of phenylpropanoid metabolism.

Assessment of Physiological and Phytochemical Traits of Purple Coneflower (&lt;i&gt;Echinacea purpurea&lt;/i&gt; L. Moench) in Response to Salicylic Acid and Methyl Jasmonate Application

Salicylic-acid and methyl-jasmonate are phytohormonal eilicitors that play important roles in regulating a number of physiological and phytochemical processes.&nbsp;For this purpose, a research was conducted as factorial based on complete randomized block design (CRBD) with three replications at the research field of agricultural faculty of University of Zanjan&nbsp;during farming years of 2017～2018 and 2018～2019. The first factor was salicylic-acid (0 (control), 50, 100 and 150 mM) and the second factor was methyl-jasmonate (0 (control), 50, 100 and 200 &micro;M). In the first year of experiment, treatments were sprayed on plants (four plants per plot) in two stages (20 days apart). In the second year they were also sprayed on remaining plants as the first year. Results of ANOVA as factorial-split in time showed that at the level of one percent ( p&lt;0.01 ), the effect of salicylic-acid on catalase, peroxidase and superoxide dismutase enzymes traits and the effect of methyl-jasmonate on antioxidant activity and catalase enzyme traits and the interaction of salicylic-acid and methyl-jasmonate on antioxidant activity, catalase, peroxidase and superoxide dismutase enzymes traits were significant. Also, at the level of five percent ( p&lt;0.05 ), the effects of methyl-jasmonate on superoxide dismutase enzyme trait was significant. The interaction of salicylic-acid and methyl-jasmonate factor was also significant on total protein trait at the level of 10 percent ( p&lt;0.1 ). The highest amount of chlorogenic acid in the first year was in the treatment of 100 mM of salicylic-acid and 50 &mu;M of methyl-jasmonate and the highest amount in the second year was in the treatment of 100 mM of salicylic-acid and 100 &mu;M of methyl-jasmonate. Also, the highest amount of chicoric acid in the both years was in the treatment of 100 mM of salicylic-acid and 100 &mu;M of methyl-jasmonate.

Chemosensitizing effects of methyl jasmonate on paclitaxel-resistant androgen-dependent and independent prostate cancer cell lines

The taxane-based therapy provides survival benefit in patients with metastatic prostate cancer; however, the average survival is less than 20 months due to the partial taxane-related chemoresistance. Innovative strategies are needed to overcome the chemoresistance for improved patient survival. In this project, paclitaxel-resistance was developed on androgen-independent PC3 and androgen-dependent 22Rv1 and LNCaP human prostate cancer (PCa) cell lines to investigate the efficacy of methyl jasmonate (MeJa), an anti-cancer drug, in overcoming the chemoresistance. The PCa cell lines were maintained in RPMI-1640 medium supplemented with 10% fetal bovine serum (FBS) at 37?C under 5% CO2. The cell lines were exposed to the gradually increasing doses of paclitaxel. Since the resistance on LNCaP could not be achieved, the study was continued with 22Rv1 cell line. It was demonstrated that paclitaxel-resistant cell lines overexpress ABCB1. Resistance levels of cells and MeJa activity in all resistant and parental lines were measured using CellTiter-Glo? luminescent assay. Test results were compared with Student?s t-test or analysis of variance (ANOVA). P?0.05 (two-tailed) was considered to be significant. In conclusion, MeJa showed more cytotoxicity on paclitaxel resistant PC3 (PC3-PtxR) cells than resistant 22Rv1 (22Rv1-PtxR) cells. Detection of cytotoxic effects of MeJa in overcoming paclitaxel resistance may contribute to the development of alternative new compounds for the prevention or chemosensitization of resistance to chemotherapeutics such as paclitaxel.

Effects of methyl jasmonate on the monoterpenes of Muscat Hamburg grapes and wine.

The importance of monoterpenes in grape and wine aroma has compelled researchers to focus on developing methods to increase their abundance. Recent research has revealed that exogenous elicitors can increase the contents of these compounds. This study determined the effects of methyl jasmonate (MeJA) preharvest treatments on the monoterpene profiles of Muscat Hamburg grapes and wine. A total of 27 monoterpenes were identified for Muscat Hamburg grapes and wine. The contents of most of the monoterpenes (free and glycosylated forms) in the grapes and wine increased in response to MeJA. An analysis of the expression of the genes in the terpenoid biosynthesis pathway indicated that the related biosynthetic pathways were activated by MeJA. The transcript levels of some genes were consistent with monoterpene production, including VviCSLinNer, VviGwbOciF, VviPNRLin, VviGT14 and VviUGT85A1L1. The developmental expression patterns of the VviPP2B1 and VviMYB24 transcription factor genes were positively correlated with monoterpene accumulation in ripening grapes. Our results suggest that MeJA may be useful for improving the aroma quality of grapes and wines.

SlMYC2 targeted regulation of polyamines biosynthesis contributes to methyl jasmonate-induced chilling tolerance in tomato fruit

Chilling injury (CI) is a major limiting factor in the retention of the postharvest quality of chilling-sensitive vegetables and fruit stored at low temperatures. The enhanced chilling tolerance induced by methyl jasmonate (MeJA) treatment might be related to the polyamines biosynthesis. However, the molecular mechanism of polyamines biosynthesis induced by MeJA is far from clear. Here, we found that the application of 0.05 mmol L−1 MeJA enhanced the activities of arginase, arginine decarboxylase and ornithine decarboxylase, as well as the transcripts of SlARG1, SlARG2, SlADC and SlODC, promoted the accumulations of polyamines and further inhibited CI development. In addition, polyamines induced by MeJA were strongly positively correlated with the SlMYC2 expression level. Moreover, MeJA-induced polyamines biosynthesis was largely inhibited due to the silencing of SlMYC2. The (SlMYC2-silenced + MeJA)-treated fruit possessed higher incidence and index of CI than the MeJA-treated fruit. Combining these findings with results of the principal component analysis, we concluded that SlMYC2 is involved in MeJA-induced chilling tolerance in postharvest tomato fruit by regulating polyamines biosynthesis. Furthermore, the electrophoretic mobility shift and dual-luciferase reporter assays indicated that SlMYC2 could activate the transcription of SlARG1, SlARG2, SlADC and SlODC by binding directly to G/E-box elements in their promoters. From the findings, it was revealed that the targeted up-regulation of SlARG1, SlARG2, SlADC and SlODC by SlMYC2 is involved in MeJA-induced polyamines biosynthesis, which enhances chilling tolerance in tomato fruit.