Combination Of Methyl Jasmonate Research Articles

Enhancement of in vitro production of tropane alkaloids and phenolic compounds in Hyoscyamus niger by culture types and elicitor treatments

This study aimed to determine the effects of 24-epibrasinolide (EBL) and methyl jasmonate (MJ) treatments on growth parameters and secondary metabolite synthesis in adventitious root and cell suspension cultures of Hyoscyamus niger. Therefore, different concentrations (0.5, 1 and 2 mg L−1) of EBL alone and combined with 224.3 mg L−1 (1 mM) MJ were applied to root and cell suspension cultures. 2 mg L−1 and 1 mg L−1 EBL were determined as the treatments in which the highest values were obtained in terms of growth criteria in root and cell cultures, respectively. In root cultures, the highest scopolamine accumulation (2.57 mg g−1) was obtained from the combination of 2 mg L−1 EBL and MJ, while the highest value (0.66 mg g−1) for hyoscyamine was observed in the roots treated with 1 mg L−1 EBL and MJ. In cell cultures, 2 mg L−1 EBL for scopolamine and 0.5 mg L−1 EBL for hyoscyamine were found to be the best applications and calculated as 0.51 µg g−1 and 0.28 µg g−1, respectively. EBL and MJ treatments also stimulated total phenolic content (TPC). The highest TPC in root cultures was detected as 18.01 mg g−1 with the combination of MJ while in cell cultures, maximum TPC was observed in cells applied with 2 mg L−1 EBL and MJ as 11.56 mg g−1. When EBL and MJ were applied to root and cell suspension cultures, significant changes occurred in the amount of phenolic compounds. Co-application of EBL and MJ significantly increased the amount of gallic acid, catechin, epicatechin, cinnamic acid and chlorogenic acid in root cultures. The application of 2 mg L−1 EBL was determined as the most suitable application for gallic acid, catechin, epicatechin, p-coumaric acid, and caffeic acid in cell cultures. It was also found that the metabolite production performance of adventitious roots was higher than that of cells. In conclusion, it was suggested that the use of MJ and EBL may be a promising strategy to enhance the accumulation of scopolamine, hyoscyamine and phenolics in root and cell cultures of H. niger.

Methyl jasmonate reduces cadmium toxicity by enhancing phenol and flavonoid metabolism and activating the antioxidant defense system in pigeon pea (Cajanus cajan)

Cadmium (Cd) is absorbed by plant roots from soil along with essential nutrients and affects plant growth and productivity. Methyl jasmonate (Me-JA) play important roles to mitigate Cd toxicity in plants. We have investigated the role of Me-JA to ameliorate Cd toxicity in Pigeon pea (Cajanus cajan). Plant root growth, biomass, cellular antioxidant defense system and expression of key regulatory genes in molecular and signaling process have been analyzed. Two Cajanus cajan varieties AL-882 and PAU-881 were grown at 25 °C, 16/8h light/dark conditions in three biological replicates at 5 mM Cd concentration, three concentration of Me-JA (0, 10 nM, 100 nM) and two concentrations in combination of Me-JA + Cd (10 nM Me-JA +5 mM Cd, 100 nM Me-JA +5 mM Cd). The seedlings were exposed to Cd stress consequently plants showed decrease in primary root growth (60.71%, in AL-882 and 8.33%, in PAU-881), shoot and root biomass and antioxidant enzymes activities. Me-JA treatment resulted in increased primary root growth (63.64%, in AL-882) and overall plant biomass. Oxidative stress generated due to Cd stress was counter balanced by Me-JA treatment. Me-JA reduced H2O2 free radicals formation and enhanced antioxidant enzyme activities and phenolic content in stressed seedlings. Me-JA treatment increased expression of CALM, IP3, CDPK2, MPKs (involved in calcium and kinase signaling pathways) and reduced expression of metal transporters (IRT1 and HMA3) genes. This reduction in metal transporters gene expression is a probable reason for low toxicity effect of Cd in root after Me-JA treatment which has potential implications in reducing the risk of Cd in the food chain.

Improvement of storage quality of ‘Hayward’ kiwifruit by MeJA combined with SA treatment through activation of phenylpropane metabolism

Kiwifruit are highly susceptible to pathogenic infestation, which can lead to spoilage during postharvest storage. Therefore, there is an urgent need to develop natural and efficient preservation methods. A compound preservative consisting of 10 μM MeJA (methyl jasmonate) and 1 mM SA (salicylic acid) was used to preserve kiwifruit during storage. Sensory, quality, and phenylpropane metabolism-related indicators were assessed at 20 °C during kiwifruit storage in groups treated with sterile water, MeJA, SA, or a combination of MeJA and SA. The results indicated that the hormone treatment groups exhibited varying degrees of efficacy in suppressing spoilage caused by pathogenic infestation. The combination treatment group demonstrated superior efficacy in comparison to the other treatment groups, as evidenced by its ability to suppress hardness reduction, delay decay rate, and disease index increase, retard soluble solids accumulation, activate enzymes PAL, C4H, and 4CL involved in phenylpropane metabolism and enhance total phenol content. The SA treatment group exhibited the second highest efficacy, whereas the MeJA treatment group demonstrated the lowest efficacy. The results showed that at the end of storage, the PAL activity and total phenolic content of kiwifruit in the combination treatment increased by 52.72%, 39.98%, 17.89%, and 98.19%, 22.47%, 14.93% compared to the control, MeJA and SA treatment alone, respectively. The findings of this study may serve as a theoretical foundation and technical guide for the utilization of MeJA in combination with SA during kiwifruit storage and preservation.

CsMYB Transcription Factors Participate in Jasmonic Acid Signal Transduction in Response to Cold Stress in Tea Plant (Camellia sinensis).

Low-temperature stress is an increasing problem for the cultivation of tea (Camellia sinensis), with adverse effects on plant growth and development and subsequent negative impacts on the tea industry. Methyl jasmonate (MeJA), as a plant inducer, can improve the cold-stress tolerance in tea plants. R2R3-MYB transcription factors (TFs) are considered potentially important regulators in the resistance to cold stress in plants. However, the molecular mechanisms, by which MYB TFs via the jasmonic acid pathway respond to cold stress in the tea plant, remain unknown. In this study, physiological and biochemical assays showed that exogenous MeJA application could effectively promote ROS scavenging in the tea plant under cold stress, maintaining the stability of the cell membrane. Sixteen R2R3-MYB TFs genes were identified from the tea plant genome database. Quantitative RT-PCR analysis showed that three CsMYB genes were strongly induced under a combination of MeJA and cold-stress treatment. Subcellular localization assays suggest CsMYB45, CsMYB46, and CsMYB105 localized in the nucleus. Exogenous MeJA treatment enhanced the overexpression of CsMYB45, CsMYB46, and CsMYB105 in E. coli and improved the growth and survival rates of recombinant cells compared to an empty vector under cold stress. Yeast two-hybrid and bimolecular fluorescence complementation experiments confirmed that CsMYB46 and CsMYB105 interacted with CsJAZ3, CsJAZ10, and CsJAZ11 in the nucleus. Taken together, these results highlight that CsMYB45, CsMYB46, and CsMYB105 are not only key components in the cold-stress signal response pathway but also may serve as points of confluence for cold stress and JA signaling pathways. Furthermore, our findings provide new insight into how MYB TFs influence cold tolerance via the jasmonic acid pathway in tea and provide candidate genes for future functional studies and breeding.

Effects of Exogenous Methyl Jasmonate Treatment with Polyethylene Bag Storage on Decay Reduction and Enhanced Total Ascorbic Acid, Total Phenolic, and Antioxidant Activities in ‘Kamphaeng Saen 42’ Mulberry Fruit

Mulberry fruit has a short shelf life of only 1 - 2 days under room conditions, make it one of the most fragile and extremely perishable fruits. This study investigated the effects of exogenous methyl jasmonate (MeJA) combined with polyethylene bag (PE) on postharvest decay, total ascorbic acid, total phenolic, anthocyanin, and antioxidant activities in 'Kamphaeng Saen 42’ mulberry fruits. The study was conducted at Postharvest Quality and Storage System Laboratory, Division of AgriScience and Technology (Postharvest Technology), Faculty of Bioresources and Technology, King Mongkut’s University of Technology Thonburi in December 2019. The experiment was laid out in Completely Randomized Design (CRD) with 4 replicates and 2 treatments consisting of 1) untreated with MeJA (control) and 2) fruits treated with 10 mmol L-1 methyl jasmonate (MeJA) combination with polyethylene bag (PE) and maintained at 10 ± 2 °C, 90 ± 2 % relative humidity (RH). The results showed that treating the mulberry fruits with 10 mmol L-1 MeJA before placing them in the PE bag was the most effective method to reduce fruit decay and also resulted in higher levels of total ascorbic acid, total phenols, and antioxidant activities than in the control at the end of storage (55.14 mg/100 g FW, 43.78 mg GAE /g FW and 28.91 mM TE /100 g FW), respectively. However, the treated fruits showed lower anthocyanin content than the control during the first 8 days of storage. These results suggest that the combination of MeJA with PE bag is beneficial in reducing fruit decay and increasing total ascorbic acid, total phenols, and antioxidant activities in 'Kamphaeng Saen 42’ mulberry fruits during storage at 10 ± 2 °C, 90 ± 2 % RH for 10 days.
 HIGHLIGHTS
 
 Mulberry fruit is one of the most fragile and extremely perishable fruits resulting in its has short shelf life
 Exogenous MeJA combined with PE bag were applied to decay reduction and enhanced total ascorbic acid, total phenolic, and antioxidant activities in ‘Kamphaeng Saen 42’ mulberry fruit
 Mulberry fruits treated with 10 µmolL-1 MeJA combined with PE bag were the most effective in reducing fruit decay and increasing total ascorbic acid, total phenols, and antioxidant activities in 'Kamphaeng Saen 42’ mulberry fruits
 
 GRAPHICAL ABSTRACT

The potential use of methyl jasmonate, putrescine and cold atmospheric plasma on genetic variability and seedling growth improvement in medicinal plant Catharanthus roseus L. cultivar

Madagascar Periwinkle (Catharanthus roseus) as a medicinal plant produces more than 100 monoterpenoid indole alkaloids. In present study, six groups including; control, Cold atmospheric plasma, methyl jasmonate hormone, putrecsine, combination of methyl jasmonate and cold plasma, and putrecsine and cold plasma treated plants were studied. Seed germination, morphological traits, catalase and peroxidase enzyme activities and amount of total alkaline were investigated in treated plants. Genetic variation of treated and control plants were evaluated by 21 coding targeted markers; Sequence related amplified polymorphism (SRAP) and Target related amplified polymorphism (TRAP). Cold plasma + putrescine treated plants showed highest amount of stem length as well as leaf length and wide size. Peroxidase and catalase activities were significantly increased in treated plants of putrescine + cold plasma and methyl jasmonate treated plants respectively. Total alkaline was significantly higher in treated plants of putrescine, and putrescine + cold plasma. In both TRAP and SRAP molecular markers, treatments of methyl jasmonate + plasma and putrescine + cold plasma had the highest level of genetic polymorphism and both markers showed moderate discriminating power to differentiate plants treated from each other. The putrescine + cold plasma is one of the best treatments for improved germination rate and seedling growth as well as enzyme activity and amount of alkaloid in C. roseus plants as well as higher genetic variation.

Alkaloids production and antioxidant properties in Catharanthus roseus (L.) G. Don. shoots and study of alkaloid biosynthesis-related gene expression levels in response to methyl jasmonate and putrescine treatments as eco-friendly elicitors.

This study aimed to determine the effects of methyl jasmonate (MJ) combined with putrescine as eco-friendly elicitors on secondary metabolism and gene expression of alkaloid biosynthetic pathway in Catharanthus roseus in vifro-propagated shoots. The expression of mitogen-activated protein kinase 3 and the transcription factor, octadecanoid-responsive Catharanthus AP2-domain3, upstream of plant alkaloids' biosynthetic pathway, and of key genes in the pathway (CrPRXl, STR, DAT, and GS) are investigated as well using qRt-PCR. Antioxidant enzyme (superoxide dismutase, peroxidase, and catalase) activities and non-enzymatic antioxidants (phenolics, flavonoids, and carotenoids) contents have studied to determine the stress levels of the plant by spectrophotometer. Results showed increased contents of non-enzymatic antioxidants after 4-8 hr and enzymatic antioxidants activities after 24 hr. Alkaloids contents increased mostly after 1 week. The investigated signaling genes upregulated after 8 hr and biosynthetic genes after 24 hr of treatments. Combined treatments had more positive effects on gene expression levels, antioxidant responses, and secondary metabolite production than MJ individually. Increased effects of combined elicitor on genes expression may be due to cross talks between their signaling pathways. Combination of MJ and putrescine can be used as an eco-friendly elicitor for enhancing the production of economically important alkaloids in C. roseus.

Endophytic Bacteria Isolated from Panax ginseng Improves Ginsenoside Accumulation in Adventitious Ginseng Root Culture.

Ginsenoside is the most important secondary metabolite of ginseng. Natural sources of wild ginseng have been overexploited. Although root culture could reduce the length of the growth cycle of ginseng, the number of ginsenosides is fewer and their contents are lower in adventitious roots of ginseng than that in ginseng cultivated in the field. In this study, we investigated the effects of endophytic bacterial elicitors on biomass and ginsenoside production in adventitious roots cultures of Panax ginseng. Endophyte LB 5-3 as an elicitor could increase biomass and ginsenoside accumulation in ginseng adventitious root culture. After 6 days elicitation with a 10.0 mL of strain LB 5-3, the content of total ginsenoside was 2.026 mg g−1 which was four times more than that in unchallenged roots. The combination of methyl jasmonate and strain LB 5-3 had a negative effect on ginseng adventitious root growth and ginsenoside production. The genomic DNA of strain LB 5-3 was sequenced, and was found to be most closely related to Bacillus altitudinis (KX230132.1). The challenged ginseng adventitious root extracts exerted inhibitory effect against the HepG2 cells, which IC50 value was 0.94 mg mL−1.

Assessment of genetic fidelity and composition: Mixed elicitors enhance triterpenoid and flavonoid biosynthesis of Glycyrrhiza uralensis Fisch. tissue cultures.

Glycyrrhiza uralensis has acquired significant importance due to its medicinal properties and health function. In this study, the quality of G. uralensis adventitious roots was evaluated in terms of genetic stability, active compounds, and anti-inflammatory activity. Monomorphic banding pattern obtained from the mother plant and tissue cultures of G. uralensis with randomly amplified polymorphic DNA markers confirmed the genetic stability of adventitious roots. Neoliquiritin (neoisoliquiritin), ononin, liquiritin, and glycyrrhizic acid were identified from G. uralensis adventitious roots on the basis of high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry analysis. This study also revealed that adventitious roots possessed a better anti-inflammatory effect than native roots. To increase the contents of G. uralensis active components, elicitors were used in the adventitious roots culture. The combination of methyl jasmonate and phenylalanine synergistically stimulated the accumulation of glycyrrhetinic acid (0.22 mg/g) and total flavonoid (5.43 mg/g) compared with single treatment. In conclusion, G. uralensis adventitious roots can be an exploitable system for the production of licorice.

Synergistic effect of methyl jasmonate and cyclodextrins on anthraquinone accumulation in cell suspension cultures of Morinda citrifolia and Rubia tinctorum

Plant in vitro culture is a platform for producing secondary metabolites that combines safety, quality and low environmental impact. Besides, it is possible to increase the accumulation of these compounds by different strategies, such as elicitation. In this work, we analyzed the effects of the combination of methyl jasmonate (MeJ) and two cyclodextrins (CDs) on the production of anthraquinones (AQs) in cell cultures of Rubiaceae (Morinda citrifolia and Rubia tinctorum). These secondary metabolites have been traditionally used as dyes and have interesting therapeutic applications. The experiments were designed according to a full factorial design of two factors (MeJ and a CD) in two levels (0 and 0.1 mM for MeJ, and 0 and 20 mM of the CD). MeJ and (2-hydroxypropyl)-β-cyclodextrin (HPCD) synergistically increased intracellular AQ content in suspension cultures of R. tinctorum, and, to a lesser extent, in suspension cultures of M. citrifolia. Combination of MeJ with another CD, 2-methyl-β-cyclodextrin, led to a more intense and later increase in AQ content in cell cultures of R. tinctorum when compared to MeJ–HPCD treatment. However, the combination of CD and MeJ failed to induce a drastic AQ release to the culture media. Nevertheless, our results show that combination of strategies (using a CD and MeJ) was successful to increase secondary metabolite accumulation in suspension cultures. To our knowledge, this is the first report of synergistic effect of MeJ and CD on AQ accumulation in plant in vitro cultures.

Physicochemical and Thermodynamic Characterization of the Encapsulation of Methyl Jasmonate by Natural and Modified Cyclodextrins Using Reversed-Phase High-Pressure Liquid Chromatography

Although the combinations of methyl jasmonate (MeJA) and cyclodextrins (CDs) have been used by different authors to stimulate the production of several metabolites, no study has been published about the possible formation of MeJA-CD complexes when these two molecules are added together to the reaction medium as elicitors. For this reason and because knowledge of the possible complexation process of MeJA with CD under different physicochemical conditions is essential if these two molecules are to be used in cell cultures, this paper looks at the complexation of MeJA with natural and modified CDs using a reversed-phase high-pressure liquid chromatography (RP-HPLC) system. The interaction of MeJA with β-CD was more efficient than with α- and γ-CDs. However, a modified CD, HP-β-CD, was the most effective of all of the CDs tested. Moreover, MeJA formed complexes with CD with a 1:1 stoichiometry, and the formation constants of these complexes were strongly dependent upon the temperature of the mobile phase used but not the pH. To obtain information about the mechanism of the affinity of MeJA for CD, the thermodynamic parameters ΔG°, ΔH°, and ΔS° were calculated. Finally, molecular modeling studies were carried out to propose which molecular interactions are established in the complexation process.

Volatile organic compounds for the control of Meloidogyne exigua in Coffea arabica

Meloidogyne exigua is a plant-parasitic nematode that causes great losses to coffee farmers. Thus, to contribute to the development of new products to control this parasite, the present work studied the effect of volatile organic compounds (VOC) on the nematode and coffee plants (Coffea arabica), since these compounds are known to be used in plant defense against other agronomical pests. The number of galls of M. exigua was reduced when the aerial part of coffee plants was sprayed with combinations of methyl jasmonate + jasmone, (Z)-hex-3-en-1-ol + (E)-hex-3-en-1-ol + (Z)-hex-2-en-1-ol + (E)-hex-2-enal, (E)-hex-2-enyl acetate + hexyl acetate, meso-butane-2,3-diol + butane-1,2-diol + butane-1,3-diol + butane-1,4-diol, 3-hydroxybutan-2-one + 4-hydroxybutan-2-one or linalyl acetate + nerolidol. These VOC also caused alterations in the concentrations of substances such as alkaloids, phenols, amino acids and carbohydrates, in the roots of coffee plants. The findings suggest that these VOC may be explored as potential products for the control of M. exigua in coffee plants.

Increasing the Phenolic Compound Content of Grapes by Preharvest Application of Abcisic Acid and a Combination of Methyl Jasmonate and Benzothiadiazole

Benzothiadiazole (BTH) and methyl jasmonate (MeJ) have been described as exogenous elicitors of some plant defense compounds, polyphenols among them. Given that they activate different arrays of biochemical reactions to induce resistance, the objective of this study was to determine whether the joint application of BTH and MeJ to grape clusters affects the level of the main flavonoid compounds in grapes and in the resulting wines. The results are compared with those obtained when abscisic acid (ABA), a plant growth regulator involved in several physiological processes, was sprayed in the same vineyard. The results obtained indicated that, although the application of ABA increased the content of skin anthocyanins and tannins, these positive effects were not reflected in the wines made from these grapes. BTH+MeJ-treated grapes also presented higher anthocyanin and flavonol contents, and in this case, their wines presented better chromatic characteristics that the wine made from control grapes.

Enhancement of biocontrol activity of Torulaspora delbrueckii with methyl jasmonate against apple blue mould disease

Torulaspora delbrueckii alone and in combination with methyl jasmonate was applied to the control of Penicillium expansum. For evaluation of direct effect of Methyl jasmonate on mycelial growth of pathogen, it was added to potato dextrose agar culture at different concentrations. Effect of methyl jasmonate on population of yeast in nutrient yeast dextrose broth media was determined after 24 and 48 h. Results showed that methyl jasmonate had no significant direct effect on pathogen and yeast. Also, evaluation of methyl jasmonate effect on the population of yeast in apple wounds indicated that methyl jasmonate at different concentrations increased population growth of yeast at 20°C, 8 and 15 days after inoculation in toward the control and it had no significant effect on population dynamics of yeast at 4°C. In vivo, the results indicated that combination of methyl jasmonate with antagonistic yeast reduced the blue mould of apples better than methyl jasmonate and yeast alone.

Enhanced killing of cervical cancer cells by combinations of methyl jasmonate with cisplatin, X or alpha radiation

Current therapies for treatment of advanced cervical cancer involve the use of cisplatin, often in combination with radiotherapy. These treatments do not lead to a high survival rate and furthermore, serious side effects are dose-limiting factors. Methyl jasmonate (MJ) was recently identified as potent and selective cytotoxic agent towards cervical cancer cells. In the present study we evaluated the effectiveness of combined treatments of MJ with cisplatin or X-irradiation on a variety of cervical cancer cells including SiHa, CaSki, HeLa and C33A. Cytotoxicity of alpha particles, emitted from (224)Ra atoms, was also evaluated as a single agent and in combination with MJ. Cooperation between MJ and cisplatin in reducing cell viability (XTT assays) and survival (clonogenicity assays) was exhibited towards several cancer cell lines at a range of combination doses. MJ effectively cooperated also with X-ray irradiation, significantly lowering the radiation doses required to inhibit cell survival (ID50) of all tested cells lines. We show for the first time, that alpha irradiation selectively reduced cell viability and survival of cervical cancer cells. Lower doses of α irradiation were required as compared to X-irradiation to inhibit cell survival. Cooperation with MJ was demonstrated in part of the cancer cell lines. In conclusion, our studies point to α irradiation and MJ, novel anticancer agents, as potent candidates for treatment of cervical cancer, in single agent regiments and in combination. MJ can be added also to conventional X-ray and cisplatin therapies to increase their cytotoxic effect while lowering the effective dose.

Methyl jasmonate down-regulates survivin expression and sensitizes colon carcinoma cells towards TRAIL-induced cytotoxicity

Methyl jasmonate (MJ) is a plant stress hormone with selective cytotoxic anti-cancer activities. The TNF-related apoptosis-inducing ligand (TRAIL) death pathway is an attractive target for cancer therapy. Although TRAIL receptors are specifically expressed in primary cancer cells and cancer cell lines, many types of cancer cells remain resistant to TRAIL-induced cytotoxicity. Here we have assessed a possible synergy between MJ and TRAIL cytotoxicity in colorectal cancer (CRC) cell lines. CRC cell lines were pre-incubated with sub-cytotoxic concentrations of MJ followed by TRAIL administration. Cell death was determined by XTT assay and microscopy. Cytochrome c release, caspase cleavage, TRAIL-associated factors, X-linked inhibitor of apoptosis (XIAP) and survivin protein levels were detected by immunoblotting. Survivin transcription was examined by RT-PCR. Pre-treatment with MJ resulted in increased TRAIL-induced apoptotic cell death, increased cytochrome c release and caspase cleavage. TNFRSF10A, TNFRSF10B, TNFRSF10D, Fas-associated death domain and cellular FLICE-like inhibitory protein remained unchanged during MJ-induced TRAIL sensitization, whereas MJ induced a significant decrease in survivin protein levels. Overexpression of survivin prevented MJ-induced TRAIL cytotoxicity, implying a role for survivin in MJ-induced TRAIL sensitization. MJ decreased survivin mRNA indicating that MJ may affect survivin transcription. In a β-catenin/transcription factor (TCF)-dependent luciferase activity assay, MJ decreased TCF-dependent transcriptional activity. MJ, at sub-cytotoxic levels, sensitized CRC cells to TRAIL-induced apoptosis. Thus, combinations of MJ and TRAIL, both selective anti-cancer agents, have potential as novel treatments for CRC.

Predominant enhancement of apoptosis induced by methyl jasmonate in bladder cancer cells

Methyl jasmonate (MJ) has recently attracted attention as a promising antitumoral compound because of its highly specific proapoptotic properties in a wide range of malignancies. However, the high doses required to achieve a therapeutic benefit have limited its clinical development. Here, we hypothesize that the family of inhibitor of apoptosis proteins (IAPs) may inhibit MJ-mediated apoptosis in cancer cells. We combined MJ with the IAPs inhibitor, the second mitochondria-derived activator of caspases (Smac) peptide to treat bladder cancer cells. The results showed that the combination of MJ and Smac peptide enhanced the apoptosis-inducing effect in a synergistic manner by releasing and activating IAPs-bounding caspase-3. These findings suggest that the inhibition of IAPs could overcome the resistance of cancer cells to MJ.

Effect of Methyl Jasmonate in Combination with Ethanol Treatment on Postharvest Decay and Antioxidant Capacity in Chinese Bayberries

The effects of methyl jasmonate (MeJA) in combination with ethanol (EtOH) treatment on green mold rot caused by Penicillium citrinum , natural decay, and antioxidant capacity in harvested Chinese bayberries were investigated. MeJA at 10 micromol L(-1) in combination with EtOH at 22.32 micromol L(-1) was most effective in reducing green mold rot and natural decay. This combined treatment also significantly inhibited spore germination and germ tube elongation of the pathogen in vitro compared with MeJA alone or control. Meanwhile, the combination-treated bayberries exhibited highest reducing power, scavenging activities against superoxide, hydroxyl, and 1,1-diphenyl-2-picrylhydrazyl radicals, and contents of total phenolics, flavonoids, and anthocyanins as well as individual phenolic compounds. Fruit quality parameters were not significantly affected by these treatments. These results suggest that the combination of MeJA and EtOH had an additive effect in reducing postharvest decay and improving antioxidant capacity in Chinese bayberries.

Methyl jasmonate induces anthocyanin accumulation in Gynura bicolor cultured roots

Gynura bicolor DC., a traditional vegetable in Japan, is cultivated as Kinjisou and Suizenjina in Ishikawa and Kumamoto prefectures, respectively. The adaxial side of the leaves of G. bicolor grown in a field is green, and the abaxial side is reddish purple. It has been reported that these reddish purple pigments are anthocyanins. Although we established a culture system of G. bicolor, the leaves of G. bicolor plants grown under our culture conditions showed green color on both sides of all leaves. We investigated the effects of phytohormones and chemical treatments on anthocyanin accumulation in cultured plants. Although anthocyanin accumulation in the leaves was slightly stimulated, anthocyanins accumulation in the roots of the cultured plant was induced remarkably by 25–50 μM methyl jasmonate (MJ) treatment. This induction was affected by light irradiation and sucrose concentration in the culture medium. However, salicylic acid (SA) and 1-aminocyclopropane-1-carboxylic acid did not induce anthocyanin accumulation in roots. And then, combinations of MJ and SA or MJ and AgNO3 did not stimulate the anthocyanin accumulation in the root as found in the case of treatment by MJ solely.

Methyl jasmonate enhances biocontrol efficacy of Rhodotorula glutinis to postharvest blue mold decay of pears

The effect of Rhodotorula glutinis treatment alone or in combination with methyl jasmonate (MeJA) in controlling blue mold decay, the natural fungal decay of pears and the postharvest quality parameters including fruit firmness, total soluble solids, titratable acidity, and ascorbic acid were investigated. The combination of methyl jasmonate (200 μM) and R. glutinis (1 × 108 CFU/ml) was a more effective approach to reduce the disease incidence and lesion diameter of blue mold decay of pears than the application of MeJA or R. glutinis alone after incubation for 7 d at 20 °C. The natural fungal decay of pears treated with the application of R. glutinis combined with MeJA resulted in reduced average decay incidence of 10.42% or 4.16%, respectively, compared with 27.17% or 20.83% in the control fruits following storage at 20 °C for 15 d or 4 °C for 60 d followed by 20 °C for 15 d. The combined treatment did not impair quality parameters of fruits under both conditions.