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Root rot of Panax notoginseng, a precious Chinese medicinal plant, seriously impacts its sustainable production. However, the molecular regulatory mechanisms employed by P. notoginseng against root rot pathogens, including Fusarium solani, are still unclear. In this study, the PnMYB2 gene was isolated, and its expression was affected by independent treatments with four signaling molecules (methyl jasmonate, ethephon, salicylic acid, and hydrogen peroxide) as assessed by quantitative real-time PCR. Moreover, the PnMYB2 expression level was induced by F. solani infection. The PnMYB2 protein localized to the nucleus and may function as a transcription factor. When overexpressed in transgenic tobacco, the PnMYB2 gene conferred resistance to F. solani. Jasmonic acid (JA) metabolism and disease resistance-related genes were induced in the transgenic tobacco, and the JA content significantly increased compared with in the wild type. Additionally, transcriptome sequencing, Kyoto Encyclopedia of Genes and Genomes annotation enrichment, and metabolic pathway analyses of the differentially expressed genes in the transgenic tobacco revealed that JA metabolic, photosynthetic, and defense response-related pathways were activated. In summary, PnMYB2 is an important transcription factor in the defense responses of P. notoginseng against root rot pathogens that acts by regulating JA signaling, photosynthesis, and disease-resistance genes.

The bioprocess methodology for the enhanced production of phytochemicals using plant cultures predominantly depends on the elicitors and precursors. The drug L-DOPA (anti-Parkinson's drug) (L-3, 4-dihydroxyphenylalanine) has been chiefly isolated from the popular medicinal plant species Mucuna. The present study has been carried out to enhance the production of L-DOPA and other secondary metabolites in the presence of the optimized concentration of growth promoters, elicitors and precursor's in vitro callus culture of Mucuna imbricata. Results revealed that there is a positive influence of Methyl Jasmonate (MJC) and Salicylic Acid (SAC) on the accumulation of L-DOPA and other secondary metabolites (Nutritional and anti-nutritional factors), which enhances their production by more than two folds. The highest accumulation of L-DOPA was noticed in the elicitation of 1 mM MJC (4.3 ± 0.4 %) followed by 1 mM SAC (3.4 ± 0.08 %) on 45th and 30th days respectively. Results also illustrated a significant increase of callus biomass (dry and moist weight) as well as total phenolics, flavonoids and antioxidants values in the elicited callus from day 30th to day 45th of explant inoculation which indicates a synergistic interaction of auxin, cytokinins with elicitors and precursors respectively. Additionally, results revealed that improved accumulation of carbohydrates was positively correlated with an increase in L-DOPA content in the elicited callus. Hence the protocol formulated delivers an effective alternative for mass production of L-DOPA from callus culture with improved metabolite content.

NAC-LIKE, ACTIVATED BY AP3/PI (NAP) is a NAC transcription factor regulating leaf senescence in Arabidopsis thaliana. In wild tobacco Nicotiana attenuata, a nuclear localized NAC transcription factor NaNAC29 was identified to be highly elicited after inoculation of Alternaria alternata, a notorious necrotic fungus on tobacco species. The NaNAC29 possesses similar tertiary structure to NAP with 60% amino acid identity. However, it remains unknown the role of NaNAC29 in plant defense responses to A. alternata and leaf senescence in N. attenuata. In this paper, Defensin-like protein 1 (NaDLP1) was highly induced in N. attenuata after A. alternata inoculation and bigger lesions were developed in NaDLP1-silenced plants. Interestingly, A. alternata-induced NaDLP1 was reduced by 76% in VIGS NaNAC29 plants and by 61% in JA deficient irAOC plants at 3 days post inoculation. The regulation of NaDLP1 expression by NaNAC29 was clearly independent on JA pathway, since exogenous methyl jasmonate treatment could not complement the induction levels of NaDLP1 in NaNAC29-silenced plants to the levels in WT plants. Otherwise, the expression of NaNAC29 was low expressed in young leaves but highly in senescent leaves and dark-treated leaves. NaNAC29-silenced plants, which were generated by virus-induced gene silencing (VIGS NaNAC29), showed delayed senescence phenotype. In addition, constitutive over-expression of NaNAC29 in A. thaliana could rescue the delayed-senescence phenotype of nap and caused precocious leaf senescence of wild-type Col-0 plants. All the data above demonstrate that NaNAC29 is a NAP homolog in N. attenuata participating in the defense responses to A. alternata by regulation of a defensin protein NaDLP1 and promoting leaf senescence.

Eclipta prostrata (L.) L. is widely used in traditional medicine for treatment of hepatitis, poisoning from snake bites and viral infections. Pharmacological studies confirmed its antioxidant, anti-inflammatory and anticancer activities. The efficacy of E. prostrata (L.) L. extracts has been correlated to phenylpropanoids such as flavonoids, coumestans and caffeoylquinic acid derivatives. In this work, the production of wedelolactone, demethylwedelolactone and 3,5-di-O-caffeoylquinic acid (3,5-diCQA) in hairy root cultures of E. prostrata (L.) L. C19 clone was increased after addition of eliciting agents jasmonic acid (JA) or methyl jasmonate (MeJA) at multiple concentrations. Cultures elicited with 100 μM of JA saw a 5.2 fold increase in wedelolactone (from 0.72 to 3.72 mg/g d.w.), a 1.6 fold increase in demethylwedelolactone (from 5.54 to 9.04 mg/g d.w.) and a 2.47 fold increase in 3,5-diCQA (from 18.08 to 44.71 mg/g d.w.). Obtained data validate the potential of E. prostrata (L.) L. hairy root cultures as a production system of wedelolactone, demethylwedelolactone and especially 3,5-diCQA, which has recently been reported to possess activity against coronavirus disease (Covid-19) by in silico computational studies. The goal of this work was to evaluate the effect of jasmonic acid (JA) or methyl jasmonate (MeJA) on wedelolactone, demethylwedelolactone and 3,5-di-O-caffeoylquinic acid (anti-Covid-19 drug candidate) production from hairy root cultures of Eclipta prostrata (L.) L. C19 clone.

Suitable postharvest treatment methods were investigated to improve the color of grape berries. Culture solutions containing jasmonic acid (JA), methyl jasmonate (MeJA), and prohydrojasmon (PDJ) enhanced the skin coloration of grape berries (‘Pione’) harvested at the initial stage of coloration. MeJA vapor treatment under sealed conditions increased anthocyanin accumulation in grape berries (‘AkiQueen’ and ‘Pione’) harvested at the early stage of skin coloration. Furthermore, promoting skin coloration by MeJA vapor treatment was as effective in mature clusters as it was in detached berries. These effects were confirmed in light conditions but not in constant darkness. Our results showed that postharvest MeJA vapor treatment improved skin coloration in grapes. In addition, postharvest treatment with MeJA was found to have no effect on the endogenous abscisic acid content of grape berry skins. Therefore, we suggest that MeJA vapor treatment can be a useful and labor-saving method for the horticultural industry.

Methyl jasmonate (MeJA) has been widely used to improve the biosynthesis of secondary metabolites such as triterpenoid saponins in medicinal plants. However, the underlying molecular mechanisms remain poorly understood. Differing from roots that accumulate protopanaxatriol-type saponins, Panax notoginseng leaves with a lower biomass mainly contain protopanaxadiol (PPD)-type saponins. Therefore, it is interesting to explore whether MeJA can activate the biosynthesis of PPD-type saponins in P. notoginseng leaves. In this study, we found MeJA could effectively induce the accumulation of PPD-type saponins, including ginsenoside Rb1, Rc, Rb2, Rb3 and notoginsenoside Fa, Fe in P. notoginseng leaves based on a newly established high-performance liquid chromatography method. Transcriptome analysis showed that differentially expressed genes (DEGs) induced by MeJA were mainly enriched in “terpenoid backbone biosynthesis”, “biosynthesis of unsaturated fatty acids”, “sesquiterpenoid and triterpenoid biosynthesis”, “fatty acid metabolism”, and “phenylpropanoid biosynthesis”. Furthermore, the expression profile and quantitative real-time PCR analysis of DEGs showed that MeJA could positively induce the molecular response of endogenous jasmonic acid (JA) signaling pathway, and increased PPD-type saponins mediated by MeJA in P. notoginseng leaves may be related to the high expression of FPS, SS, SE, DS and UGTs, and the low expression of CYP716A53v2 and β-AS. The results provide a molecular understanding for MeJA-elicited biosynthesis of triterpenoid saponins and facilitate the further characterization of the genes responsible for biosynthesis of PPD-type saponins in P. notoginseng leaves.

Drought is believed to be one of the most important abiotic stresses, which drastically affects wheat production worldwide. Jasmonates, as plant growth regulators, could modify the effects of environmental stresses. Therefore, we conducted the present study to investigate the physiological responses of wheat cultivars to exogenous methyl jasmonate (MeJA) under drought stress during two crop years of 2015–2017. The results revealed that the irrigation cut-off regime at the booting decreased Fv/Fm, RWC, peroxidase activity, and grain yield; whereas it increased proline, malondialdehyde content, protein, and electrolyte leakage. The drought-tolerant cultivar, Sirvan had 13.7% higher grain yield than Pishtaz cultivar in drought stress owing to higher Fv/Fm, proline, RWC, peroxidase activity, and lower electrolyte leakage and MDA. Spraying 50 μM of MeJA increased chlorophyll and carotenoids (8.7% and 6.93%), proline (26.8%), and peroxidase activity (31.4%); whereas 100 μM of MeJA increased the RWC (2.5%), Fv/Fm (9.3%) and decreased membrane electrolyte leakage (6.7%) compared to hormone-free conditions. According to the results drought stress decreased certain physiological traits, the foliar application with 100 μM of MeJA could increase the grain yield (9.2% in irrigation cut-off at booting and 6.8% at the milk stage) and then partially compensate for the reduction caused by drought stress. Therefore, for minimizing the effect of drought stress, we could recommend the use of MeJA and drought-tolerant cultivar.

The present study was conducted to investigate the effects of methyl jasmonate (MeJA) dipping treatment on mitochondrial energy metabolism and quality parameters of Nanguo pears during room temperature storage. The results showed that MeJA treatment suppressed the respiration rate and weight loss, and maintained the flesh firmness of Nanguo pears. MeJA also effectively maintained the content of ascorbic acid and titratable acidity in the fruit. Furthermore, the activities of H+-ATPase, Ca2+-ATPase, succinate dehydrogenase (SDH) and cytochrome C oxidase (CCO) of the MeJA-treated fruit were significantly higher than those of the untreated fruit. The contents of adenosine triphosphate (ATP) and adenosine diphosphate (ADP) and the energy charge were also enhanced by MeJA treatment. These results suggest that postharvest MeJA treatment could maintain the quality of Nanguo pears, in part by modulating mitochondrial energy metabolism during room temperature storage.

Catharanthus roseus is a very rich source of medically important alkaloids. However, since their concentrations are extremely low in plant tissues, many efforts have been made to increase the alkaloids level - among them are the application of various elicitors. Since the alkaloids are synthetized by a complex pathway, the detailed knowledge of the molecular background of the system is essential. The current job aimed to study the effect of two elicitor, methyl jasmonate (MeJa) and UV-B irradiation, and also their simultaneous effect, on the expression patterns of two key synthesis-involved genes, namely tryptophan decarboxylase and strictosidine synthase through quantitative RT-PCR. Estimation of vinblastine, vincristine and ajmalicine, was carried out using high performance liquid chromatography (HPLC) in the elicited plant leaves. From the obtained results, it was concluded, that these two elicitors act on different way, and also their combined application induces the tryptophan decarboxylase but in less for the strictosidine synthase gene expression in the treated Catharanthus roseus leaves. The results showed that the combination of MeJa and UV-B light (MU) induces higher accumulation of vinblastine,vincristine and ajmalicine than other treatments. Vinblastine content with MU60 treatment showed higher level during the third day of exposure to the combined elicitors (methyl jasmonate and UV-B). Vincristine accumulation was the highest after one day of exposure to MU60 treatment. Its content was increased 6-fold than control after one day exposure to the combined elicitors. Additionally, it could be observed that MU60 treatment, was the best for ajmalicine accumulation. Ajmalicine content was increased 8-fold than control at 60 min exposure to the combined elicitors. As a final outcome, we also conclude that the effect of the different elicitations is highly dependent on the experimental parameters.

Flavonoids are important metabolites of pigeon pea in relation to its stress resistance. However, the molecular basis and regulatory mechanisms of flavonoids in pigeon pea remain unclear. Methyl jasmonate (MeJA) is a signaling molecule associated with biosynthesis of flavonoids. In this study, after exogenous treatment of 10 mg/L MeJA, infection of pathogenic fungi to pigeon pea was alleviated and the content of flavonoids was increased. Results of gene expression and metabolic changes that were respectively analyzed by transcriptome sequencing and high performance liquid chromatography (HPLC) showed that (1) concentrations of various flavonoids, such as genistein, apigenin, vitexin and biochanin A were significantly up-regulated; (2) 13675 differentially expressed genes were produced, mainly enriched in signal transduction and isoflavone biosynthesis pathways: (3) the expression levels of key synthase genes (CcI2′H, CcHIDH, Cc7-IOMT) in the flavonoid biosynthesis pathway were significantly up-regulated; (4) Overexpression of CcbHLH35 significantly induced upregulation of flavonoid synthase genes and accumulation of genistein, vitexin and apigenin. Our findings reveals the pivotal roles of MeJA in synthesis and functioning of flavonoids in pigeon pea, which provide a basis for further studies on flavonoid-mediated defense responses.

In the present study, the 5′-regulatory region of chalcone isomerase gene (MusaCHI-1) of banana was functionally analysed for its tissue specific, stress mediated and strong guard cell preferred activity. Expression of MusaCHI-1 was altered in leaves of banana plants exposed to various stress conditions and signalling molecules. Transgenic lines of tobacco harbouring PMusaCHI-1-GUS displays prominent GUS staining in vascular region and guard cells of leaves which corroborates with array of Dof1 binding cis-elements in PMusaCHI-1 region. Multiple cis-elements associated with various stress conditions were detected in PMusaCHI-1 which directly correlates with alteration of MusaCHI-1 transcript level in banana exposed to stress conditions. GUS staining of transgenic tobacco plants harbouring PMusaCHI-1-GUS and exposed to drought, salinity, and applications of methyl jasmonate and abscisic acid indicated activation of PMusaCHI-1 under these conditions while exposure of salicylic acid strongly suppresses GUS expression from PMusaCHI-1.

This study evaluates phytoecdysteroid (PE) biosynthesis stability and the effect of methyl jasmonate (MJ) on changing their accumulation over 25 subculture cycles of Silene linicola hairy roots. High performance liquid chromatography was used to determine PE content. We find a significant change in the biosynthesis level of PEs as a whole, as well as individual components such as 20-hydroxyecdysone (20E) and turkesterone, under prolonged cultivation of S. linicola hairy roots. The maximum 20E content was observed in a sample of the 7th subcultivation cycle (0.189%), whereas the maximum level of turkesterone—the 9th cycle (0.044%). We found that without application of MJ, the main component of total PEs in hairy roots becomes 20E during the 7th to 25th subcultivation cycles, with percentages of 51.9; 25.4; 79.1 and ~ 100% in 7th, 9th, 21st and 25th cycles, respectively. Using the elicitor changes this pattern. The smallest ratio of 20E to the PE sum was 8.2% and turkesterone becomes the major component (53%), detected during the 9th passage treated with MJ. Our data suggest that total PE and individual component content should be monitored along with 20E level, as biosynthetic activity of these components in S. linicola hairy roots varies with cultivation stage.

Methyl jasmonate treatment and aphid resistance assays reveal different roles in herbivore defensive responses between tobacco glandular and non-glandular trichomes. These roles correlate with trichome gene expression patterns. In plants, trichomes greatly contribute to biotic stress resistance. To better understand the different defensive functions between glandular and non-glandular trichomes, we used Nicotiana tabacum as a model. This species bears three types of trichomes: long and short stalk glandular trichomes (LGT and SGT, respectively), and non-glandular trichomes (NGT). Tobacco accession T.I.1068 (lacking NGT) and T.I.1112 (lacking LGT) were used for the experiment. After methyl jasmonate (MeJA) treatment, LGT formation was promoted not only in T.I.1068, but also in T.I.1112, whereas NGT remained absent in T.I.1068, and was slightly reduced in T.I.1112. Diterpenoids, which play important roles in herbivore resistance, accumulated abundantly in T.I.1068 and were elevated by MeJA; however, they were not found in T.I.1112 but became detectable after MeJA treatment. The aphid resistance of T.I.1068 was higher than that of T.I.1112, and both were enhanced by MeJA, which was closely correlated with LGT density. Trichomes detached from T.I.1068 and T.I.1112 were used for RNA-Seq analysis, the results showed that pentose phosphate, photosynthesis, and diterpenoid biosynthesis genes were much more expressed in T.I.1068 than in T.I.1112, which was consistent with the vigorous diterpenoid biosynthesis in T.I.1068. In T.I.1112, citrate cycle, propanoate, and glyoxylate metabolism processes were enriched, and some defensive protein genes were expressed at higher levels than those in T.I.1068.These results suggested that LGT plays a predominant role in aphid resistance, whereas NGT could strengthen herbivore resistance by accumulating defensive proteins, and the roles of LGT and NGT are associated with their gene expression patterns.

Methyl jasmonate (MeJA) is a plant growth regulator, which plays an important role in signaling defense response and regulating plant secondary metabolism. Here, broccoli hairy roots growing for 18 d were treated with MeJA for 0, 3, 6, 9, and 12 h, respectively. Compared with the 0 h control group, the content of glucoraphanin (GRA) and sulforaphane (SF) was increased under MeJA treatment for 3, 6, 9, and 12 h. The activity of myrosinase (MYR) was reduced in broccoli hairy roots. With the broccoli (Brassica oleracea L. var. botrytis L) genome as the reference genome, 4733 DEGs (differentially expressed genes) were detected in the hairy roots that were treated by MeJA for 0, 3, 6, 9, and 12 h; among them, 1024 genes were upregulated and 3709 genes were downregulated. The pathway of “SNARE interaction in vesicular transport” (ko04130) was ranked 1st by KEGG pathway enrichment analysis of commonly upregulated differential genes at 0, 3, 6, 9, and 12 h. The expression of four key genes ABCB19, ABCG6, ABCG36, and ABCB9, which regulated the release of GRA and SF into a liquid medium, was upregulated at 0, 3, 6, and 9 h, respectively. It revealed that the release of GRA and SF from hairy roots was related to the ABC transporter gene family and SNARE protein-mediated exocytosis by transcriptome analysis.

Lipoxygenase (LOX, EC 1.13.11.12) is a non-haeme iron-containing dioxygenase family that catalyzes the oxygenation of polyunsaturated fatty acids into bio-functionally fatty acid diverse (oxylipins) and plays vital role in plant growth and development and responses to abiotic and biotic stresses. Though LOX genes have been studied in many plant species, their roles in Brassicaceae species are still unknown. Here, a set of 14, 18, and 33 putative LOX genes were identified in Brassica rapa, Brassica oleracea and Brassica napus (allotetraploid rapeseed), respectively, which could be divided into 9-LOX (LOX1/5), 13-LOX type I (LOX3/4/6), and type II (LOX2) subgroups. There was an expansion of LOX2 orthologous genes in Brassicaceae. Most of the LOX genes are intron rich and conserved in gene structure, and the LOX proteins all have the conserved lipoxygenase and PLAT/LH2 domain. Ka/Ks ratio revealed that the majority of LOXs underwent purifying selection in Brassicaceae. The light-, ABA-, MeJA-related cis-elements and MYB-binding sites in the promoters of BnaLOXs were the most abundant. BnaLOXs displayed different spatiotemporal expression patterns and various abiotic/biotic stress responsive expression patterns. BnaLOX1/5 were slightly or no response to phytohormones and abiotic stresses. BnaLOX3/4/6 predominantly express in roots and were strongly up-regulated by salinity and PEG treatments, and BnaLOX3/4 were the methyl jasmonate (MeJA) and salicylic acid (SA) early response genes and strongly induced by infection of Sclerotinia sclerotiorum; while the BnaLOX2 members predominantly express in stamens, were MeJA and SA continuous response genes and strongly repressed by cold, heat and waterlogging treatments in leaves. Our results are useful for understanding the biological functions of the BnaLOX genes in allotetraploid rapeseed.

Nowadays, among several abiotic stresses, salt, especially NaCl and UV-B are of major concern. They lead to deleterious effects on plant growth and ultimately affect crop productivity. The present study was planned to find out some ameliorative solution against these stresses. Here, the modulatory action of two oxylipins, namely, methyl jasmonate (MeJA) and 12-Oxo-phytodienoic acid (OPDA) on growth, photosynthetic performance, nitrate/ammonia assimilating enzymes, and nutritive values of Luffa Mill. seedlings grown under NaCl (20 and 40 mM) and/or enhanced UV-B stresses (ambient: 8.2 kJ m−2 d−1 + additional: 2.2 kJ m−2 s−1) were analyzed. Both the stresses when given alone, negatively affected the fresh mass, root/shoot ratio, leaf area, photosynthetic pigments content, photosynthetic oxygen yield and, chlorophyll a fluorescence kinetic parameter. This decline was further aggravated upon combined exposure to the stressors. However, supplementation of MeJA/OPDA effectively counteracted the negative impact on important growth-regulating processes. The activities of nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS), and glutamate synthase (GOGAT) enzymes, as well as the contents of inorganic nitrogen, protein, and carbohydrate, were increased with the supplementation of MeJA/OPDA. The increase in the Na+ and Cl‾ contents due to NaCl or/and UV-B was depreciated by MeJA or OPDA. Ameliorating behaviour of MeJA or OPDA is correlated with improved photosynthetic activity and nitrogen metabolism. These findings, point out that supplementation of MeJA/OPDA, particularly OPDA more favourably regulated the growth-promoting activities, which can be linked with the mitigation of NaCl and UV-B stress.

The Rosa hybrida L. is an attractive cut flower that has a short vase life due to the decrease in its quality during the post-harvesting storage. Therefore, the current study aimed to explore the effectiveness of pre-harvest MeJA and 24-epibrassinolide (EBR) application on different post-harvest quality characters, gray mold disease, and vase life of cut roses. The experiment was conducted as a split-plot in time based on a complete randomized design with three replications. The two experimental factors were included treatment [water, 0.1 and 0.2 µm of MeJA, 1 and 2 µm of EBR, Botrytis cinerea infection (Bot), 0.1 mM MeJA + Bot, 0.2 µM MeJA + Bot, 1 µM EBR + Bot, 2 µM EBR + Bot] and, sampling time (3, 7 and 10 days after harvesting). ANOVA showed that the effects of interaction between two factors were significant on catalase (CAT) and superoxide dismutase (SOD) activities, membrane stability index (MSI), anthocyanin, total soluble sugar (TSS), relative fresh weight, and water content (RFW and RWC), and cut roses vase life (P

The MeJA has been shown to be promising in reducing the damages caused by cold and maintaining the quality in several products. Nevertheless, few studies are conducted with flowers and there are no studies of its use in bird of paradise. The objective of this study was to determine whether the pulsing application with MeJA submitted to cold storage promotes physiological changes of the bird of paradise. Flowers were placed in solutions of 200 g L-1 sucrose added with 100, 250 and 400 μmol L-1 MeJA and control without MeJA, for 24 h. The stems were transferred to containers with water at 5 ºC for 28 days. During storage, the water absorption, transpiration and fresh mass were reduced, while the extravasation of electrolytes and phenolic compounds increased. The application of MeJA did not reduce the loss of fresh mass and extravasation of electrolytes. The application of 400 μmol L-1 MeJA has increased peroxidase activity since day 14 of storage. It is concluded that the application of MeJA with pulsing under refrigeration does not promote positive physiological changes for the maintenance of the quality in bird of paradise flowers.

The objective of this study is to show the real impact of methyl jasmonate and ethephon in combination on the production of phenolic compounds in cultivar R405-2000 of the cotton plantGossypium hirsutum. As well, cotton plants were treated in the field by methyl jasmonate (MeJA), ethephon (ETH) and the association of methyl jasmonate and ethephon (MeJA + ETH). The effect of these treatments was appreciated thanks to a qualitative analysis of total phenols by High Performance Liquid Chromatography. The results showed that ethephon, the metabolic precursor of ethylene, has properties identical to those of MeJA. However, the treatment of cotton leaves with ethephon induces less phenolic compounds than MeJA. On the other hand, the co-treatment of the leaves with MeJA and ethephon leads to an induction of phenolic compounds, which accumulate in greater quantities in the plant the phenols synthesized are more important with an activation of the biosynthetic pathway of stilbenoids because trans-resveratrol and transpiceide, two compounds belonging to the group of stilbenoids were synthesized de novo by the joint application of MeJA and ethephon on cotton leaves when they could not be synthesized when these two elicitors are applied alone.

Ceratocystis wilt is a lethal disease of cacao, and the search for resistant genotypes may provide the best way to deal with the disease. Resistance or susceptibility behavior of some cacao genotypes when infected by Ceratocystis cacaofunesta is not yet understood. Herein, we report an LC-MS metabolomic screening analysis based on high-resolution MS to obtain comprehensive metabolic profile associated with multivariate data analysis of PLS-DA, which was effective to classify CCN-51 and TSH-1188 as resistant genotypes to C. cacaofunesta fungus, while CEPEC2002 was classified as a susceptible one. Using reversed-phase LC method, electrospray interface, and high-resolution tandem MS by the quadrupole-TOF analyzer, the typical profiles of metabolites, such as phenylpropanoids, flavonoids, lipids, alkaloids, and amino acids, were obtained. Untargeted metabolite profiles were used to construct discriminant analysis by partial least squares (PLS-DA)-derived loading plots, which placed the cacao genotypes into two major clusters related to susceptible or resistant groups. Linolenic, linoleic, oleic, stearic, arachidonic, and asiatic acids were annotated metabolites of infected, susceptible, and resistant genotypes, while methyl jasmonate, jasmonic acid, hydroxylated jasmonic acid, caffeine, and theobromine were annotated as constituents of the resistant genotypes. Trends of these typical metabolites levels revealed that CCN51 is susceptible, CEPEC2002 is moderately susceptible, and TSH1188 is resistant to C. cacaofunesta. Therefore, profiles of major metabolites as screened by LC-MS offer an efficient tool to reveal the level of resistance of cacao genotypes to C. cacaofunesta present in any farm around the world.

BRASSINAZOLE-RESISTANT (BZR) genes are a family that has transcription factors that are particular to plants and are involved in the signal transduction of brassinosteroids. This study identified nine BZR genes in tomato using a computational approach. BZRs are hydrophilic proteins mostly located in the nucleus. The most common secondary structure of BZRs is random coil. The number of introns contained in the BZR family genes is between 1 and 9, and these genes are distributed in a disarrayed fashion across the chromosomes, while there were two pairs of duplicated gene fragments. Forty-four cis-elements were identified in the region of the gene promoter, all of which were associated with plant hormones, tissue specific expression, response to stress, and light response. The genes in this family mainly responded to plant hormones such as gibberellin, salicylic acid, abscisic acid, auxin, and methyl jasmonate (MeJa). Analysis of the expression profile demonstrated that SlBZR gene expression was significantly different in tissues and organs at different developmental stages of tomato, and some genes had tissue specific expression. The results of qRT-PCR demonstrated that all genes in the BZR family were involved in stress response (200 mmol/L SA, 200 mmol/L ABA, and 4 °C). The results lay the foundation to further study the functions of tomato BZR genes.

As the major contributors to the floral odors of tea products, terpenoid volatiles play critical roles in the defense response of plants to multiple stresses. Until now, only a few TPS genes in tea plants (Camellia sinensis) have been functionally validated. In this study, by comparative studies conducted at gene, protein, and metabolite levels during oolong tea processing, we isolated an ocimene synthase gene, CsOCS, which displays a low similarity to previously characterized tea ocimene synthases. Further prokaryotic expression and subcellular localization analysis showed that it is plastid-located and could produce (E)-β-ocimene and (Z)-β-ocimene using GPP as the substrate. The optimum temperature and pH of the enzyme were 30 °C and 7.5, respectively. Treatment with exogenous methyl jasmonate elevated the transcript level of CsOCS and enhanced the emission of ocimene from tea leaves. Collectively, CsOCS is implicated as a key enzyme for β-ocimene synthesis during oolong tea processing.

In Pinus radiata, both primary and secondary compounds may play a role in defence against herbivory. Allocation of constitutive and induced primary and secondary compounds varies among needles, bark and roots. Responses to stresses are stronger in primary than secondary compounds and some responses of root chemistry to above-ground stressors were detected. The capacity of trees to cope with pests and pathogens depends in part on the variation of constitutive and induced chemical defences within the plant. Here we examined the constitutive and induced variation of primary (sugars and fatty acids) and secondary (mono-, sesqui- and di- terpenoids as well as volatile phenolics) metabolites in the needles, bark and, for the first time, roots of 2-year old Pinus radiata. A total of 81 compounds were examined. The plant parts differed significantly in constitutive levels of individual sugars, fatty acids, mono-, sesqui- and di- terpenoids as well as volatile phenolics. Overall, the bark had more compounds and a higher amount of most secondary compounds and the levels of compounds in the roots differed from that of the needles and bark. For example, glucose was the dominant sugar in the needles and bark whereas fructose dominated in the roots. Of the fully identified secondary compounds, monoterpenoids dominated in all plant parts but with different qualitative patterns. Following methyl jasmonate and bark stripping treatments, a marked reduction in sugars but weaker changes in secondary compounds were detected in the needles and bark. Responses in the roots were minor but the few that were detected were mostly in response to the bark stripping treatment. Changes in correlations among chemicals within plant parts and between the same compound across the different plant parts were also detected after stress treatments. Overall, results showed that the constitutive composition in the roots differs from that of the bark and needles in P. radiata and inducibility is stronger in the primary than secondary metabolites and differs between plant parts. This detailed assessment of Pinus radiata chemistry in the needles, bark and roots, including the compounds that respond to simulated biotic stress will potentially facilitate the identification of related chemical defence traits.

Jasmonate (JA)-induced plant senescence has been mainly studied with a dark/starvation-promoted system using detached leaves; yet, the induction of whole-plant senescence by JA remains largely unclear. This work reports the finding of a JA-induced whole-plant senescence of tobacco under light/non-starvation conditions and the investigation of underlying regulations. Methyl jasmonate (MeJA) treatment induces the whole-plant senescence of tobacco in a light-intensity–dependent manner, which is suppressed by silencing of NtCOI1 that encodes the receptor protein of JA-Ile (the bioactive derivative of JA). MeJA treatment could induce the senescence-specific cysteine protease gene SAG12 and another cysteine protease gene SAG-L1 to high expression levels in the detached leaf patches under dark conditions but failed to induce their expression in tobacco whole plants under light conditions. Furthermore, MeJA attenuates the RuBisCo activase (RCA) level in the detached leaves but has no effect on this protein in the whole plant under light conditions. A genome-wide transcriptional assay also supports the presence of a differential regulatory pattern of senescence-related genes during MeJA-induced whole-plant senescence under non-starvation conditions and results in the finding of a chlorophylase activity increase in this process. We also observed that the MeJA-induced senescence of tobacco whole plants is reversible, which is accompanied by a structural change of chloroplasts. This work provides novel insights into JA-induced plant senescence under non-starvation conditions and is helpful to dissect the JA-synchronized process of whole-plant senescence.

Trigonelline is the major secondary metabolite of fenugreek (Trigonella foenum-graecum L.), the exploitation of which is of great importance in the cosmetic and pharmaceutical industries. Therefore, there is a vital demand for improving the production of this metabolite. In this way, elicitation in the in vitro conditions is a compelling approach. The present study was conducted for the first time to investigate the effect of osmotic stresses (salinity and drought) and elicitors (pectin, chitin, methyl jasmonate (MJ), and salicylic acid (SA)) on the trigonelline production in callus culture of fenugreek. Most potential stimulation was done by MJ and SA; elicitation by 50 μM of methyl jasmonate for 15 days resulted in a substantial improvement (2.27 mg g−1 dry weight (DW) that is 5.6-folds over the control). The two abiotic elicitors, i.e. MJ and SA, failed to stimulate trigonelline production except for elicitation by 100 μM of pectin for 10 days and elicitation by 50 μM of chitin for 5 days. Nonetheless, a profound effect was observed between the osmotic stresses, using 200 mM of NaCl (1.93 mg g−1 DW), which was 4.7-folds over the control; however, the drought stress resulted in a maximum of twofold increase. Given the suppressing effect of osmotic stresses on callus growth, the total production of trigonelline in the calli was restricted under these treatments. Thus, our findings revealed that the elicitation by SA and MJ provides the most potent conditions to induce trigonelline production in fenugreek callus culture, as well as simultaneous increasing of callus growth.

Trehalose plays an important role in plant metabolism, growth development, and stress tolerance. Trehalose-6-phosphate synthase gene (TPS) and trehalose-6-phosphate phosphatase gene (TPP) are vital for the synthesis of trehalose. Populus is a prominent perennial woody plant, in which systematic genome-wide analysis of the TPS and TPP family is limited. In this study, 13 PtTPS and 10 PtTPP genes were identified in the Populus genome. Phylogenetic analysis indicated PtTPS and PtTPP genes were both divided into two subfamilies, and gene members of each subfamily have highly conserved intron structures. Analysis of cis-acting elements showed that PtTPS and PtTPP genes were involved in plant hormones and environmental stress responses. Expression profiles also found PtTPSs and PtTPPs expressed differently in response to salt stress, cold, mechanical damage, salicylic acid, and methyl jasmonate treatment. Furthermore, reverse transcription quantitative real-time PCR results found PtTPSs and PtTPPs displayed a specific expression pattern in the seven developmental stages of Populus male and female floral buds. This work will not only lead a foundation on reveal the functions of PtTPS and PtTPP gene families in trehalose regulation of poplar but also provide references to related trehalose research in other perennial plants.

Phenolic acids are one of the most valuable groups of bioactive compounds in Salvia species. In this work, the effect of MeJA (50 μM) and AgNO3 (15 μM) on the phenolic acids accumulation and the expression of some crucial genes involved in the synthesis of these compounds were evaluated in two Salvia species of Iran, S. officinalis and S. verticillata, as the two rich sources of phenolic acids. Twelve-leaf plantlets of the each examined Salvia species were foliar sprayed with 50 µM MeJA and 15 µM AgNO3 until they were entirely soaked. The leaf samples were then harvested after 0, 4, 8, 24, 48, and 72 hours of treatment for analyses. Results demonstrated that the application of MeJA and Ag+ considerably enhanced the accumulation of four predominant phenolic acids of rosmarinic acid (RA), caffeic acid (CA), salvianolic acid B (Sal-B), and salvianolic acid A (Sal-A) in both of the assessed species. Furthermore, Ag+ was more effective than MeJA to induce the phenolic acids accumulation in the studied Salvia plants. The expression of the principal genes (PAL, TAT, HPPR, RAS, and CYP98A14) in both of the phenylpropanoid and tyrosine pathways were affected by MeJA and Ag+ in the examined Salvia species. Our findings showed that expression levels of TAT and CYP98A14 were significantly correlated with phenolic acids production in both of the studied species after elicitation with MeJA. The results provided new information on the putative genes for the production of phenolic acids in the tested Salvia species under the elicitation of MeJA and Ag+.

Prior to Ginkgo leaf harvest, we implemented four exogenous applications of salicylic acid (SA: 50, 80, and 100 mg·L−1) or methyl jasmonate (MJ: 20, 40, and 80 mg·L−1) as leaf spray to investigate their effect on flavonoids content and related enzyme activity. Compared with the control, a significant increase of 12% and 26% in flavonoid content was observed 7 days after the first application of 100 mg·L−1 SA and 20 mg·L−1 MJ, respectively; both were determined to be the best treatments. Operationally, administering either elicitor (SA or MJ) 1 week prior to leaf harvest is deemed to be the most practical and economic option. Additionally, enzymes activity involved in flavonoid metabolism (phenylalanine ammonia-lyase, cinnamate 4-hydroxylase, and 4-coumarate:coenzyme A ligase) and antioxidants (peroxidase, superoxide dismutase, and catalase) significantly increased in most SA and MJ treatments. The results strongly support Ginkgo leaf response to SA- or MJ-induced stress through increased nonenzymatic antioxidant compounds (flavonoids) and activity of antioxidant enzymes.

The functions of ubiquitin‐conjugating enzymes (E2) in plant immunity are not well understood. In this study, OsUBC26, a rice ubiquitin‐conjugating enzyme, was characterized in the defence against Magnaporthe oryzae. The expression of OsUBC26 was induced by M. oryzae inoculation and methyl jasmonate treatment. Both RNA interference lines and CRISPR/Cas9 null mutants of OsUBC26 reduced rice resistance to M. oryzae. WRKY45 was down‐regulated in OsUBC26 null mutants. In vitro E2 activity assay indicated that OsUBC26 is an active ubiquitin‐conjugating enzyme. Yeast two‐hybrid assays using OsUBC26 as bait identified the RING‐type E3 ligase UCIP2 as an interacting protein. Coimmunoprecipitation assays confirmed the interaction between OsUBC26 and UCIP2. The CRISPR/Cas9 mutants of UCIP2 also showed compromised resistance to M. oryzae. Yeast two‐hybrid screening using UCIP2 as bait revealed that APIP6 is a binding partner of UCIP2. Moreover, OsUBC26 working with APIP6 ubiquitinateds AvrPiz‐t, an avirulence effector of M. oryzae, and OsUBC26 null mutation impaired the proteasome degradation of AvrPiz‐t in rice cells. In summary, OsUBC26 plays important roles in rice disease resistance by regulating WRKY45 expression and working with E3 ligases such as APIP6 to counteract the effector protein AvrPiz‐t from M. oryzae., Rice ubiquitin‐conjugating enzyme OsUBC26 is essential for immunity to blast fungus by regulating WRKY45 expression and working with APIP6 to promote the ubiquitination and degradation of AvrPiz‐t.

The Multidrug and Toxic Compound Extrusion (MATE) protein belongs to a secondary transporter gene family, which plays a primary role in transporting many kinds of substrates such as organic compounds, secondary metabolites, and phytohormones. MATE protein members exist in both prokaryotes and eukaryotes. However, evolution and comprehensive analysis of the MATE genes has not been performed in Rosaceae species. In the present study, a total of 404 MATEs genes were identified from six Rosaceae genomes (Prunus avium, Pyrus bretschneideri, Prunus persica, Fragaria vesca, Prunus mume, and Malus domestica) and classified into eight main subfamilies (I-VII) based on structural and phylogenetic analysis. Microcollinearity analysis showed that whole-genome duplication events might play a vital role in the expansion of the MATE genes family. The Ka/Ks analysis, chromosomal localization, subcellular localization, and molecular characteristics (length, weight, and pI) were performed using various bioinformatics tools. Furthermore, different subfamilies have different introns-exons structures, cis-acting elements, and conserved motifs analysis, indicating functional divergence in the MATE family. Subsequently, RNA-seq analysis and real-time qRT-PCR were conducted during Chinese pear fruit development. Moreover, PbMATE genes were significantly expressed under hormonal treatments of MeJA (methyl jasmonate), SA (salicylic acid), and ABA (abscisic acid). Overall, our results provide helpful insights into the functions, expansion complexity, and evolutions of the MATE genes in Chinese pear and five Rosaceae species.

Certain chemical pesticides control plant diseases through induction of systemic resistance mechanisms. In this study, orysastrobin, a “quinone outside inhibitor” (QoI)-type commercial fungicide, decreased disease severity in the leaves of A. thaliana resulting from inoculation with P. syringae pv. tomato DC3000; protection from the orysastrobin treatment correlated with lowered bacterial populations in the plant tissue. The fungicide-induced cross protection to a bacterial pathogen was at the same level as that given by foliar treatment with beta-aminobutyric acid (BABA), an inducer of salicylic acid (SA) - defense pathway, leading to induced resistance for this pathogen. Although another chemical inducer of the SA-pathway, benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH), induced the marker gene for the salicylic acid (SA) pathway PR1a, there was no induction with orysastrobin or methyl jasmonate treatments. However, orysastrobin induced AtVSP1.2, in the JA-pathway and PDF1.2 in the ET defense pathway. These findings suggested that the fungicide, orysastrobin, induced resistance to the pathogenic pseudomonad. Because orysastrobin induced the JA/ET defense pathways, applications of this strobilurin-type fungicide have the potential to protect plants from a large array of pathogens and abiotic stresses.

The Lateral Organ Boundaries Domain (LBD) proteins are a class of plant-specific transcription factor family, which participate in plant growth, development, and stress response. In present study, 61 PheLBD genes were identified in moso bamboo (Phyllostachys edulis) genome. These members clustered into two major classes (Class I and Class II) based on the previous study and phylogenetic analysis, and Class I was further divided into five subgroups (Class I–Class E). The gene architecture and conserved motifs suggested the members in one subgroup shared the structural similarities and highly conserved motif compositions. Scaffold position analysis showed PheLBDs were unevenly located on 19 moso bamboo scaffolds. Synteny analysis indicated segmental duplication and transposed duplication played significant roles in PheLBD gene expansion and some PheLBD genes have been and are undergoing markedly positive purifying selection during evolution. A large number of light-responsive elements, abiotic-stress and hormone-response elements were discovered in the promoter of PheLBDs. Public RNA-seq data helps to analyze the expression profile of PheLBD genes in 14 moso bamboo tissues. And we also found most genes in class II were significantly up-regulated under auxin naphthaleneacetic acid (NAA) treatment, but were sensitive after Gibberellins (GA)-treated. Moreover, quantitative real-time reverse transcription PCR (RT-qPCR) analysis showed that PheLBDs have different response to salt and drought stress as well as abscisic acid (ABA) and Methyl jasmonate (MeJA). Overall, these results paved a way for the further functional studies of PheLBDs.

Indirect defense is an important strategy employed by sessile plants to defend against herbivorous insects by recruiting the natural enemies of herbivores mediated by herbivore-induced plant volatiles (HIPVs). We aimed to determine whether indirect defense occurs in Compositae with Chrysanthemum morifolium as the model and elucidate the mechanisms underlying the biosynthesis of HIPVs. Using two-choice olfactometer bioassays, we showed that C. morifolium plants following infestation by larvae of the tobacco cutworm (Spodoptera litura, TCW) were significantly more attractive to two natural enemies of TCW larvae than control plants, indicating that indirect defense is an active defense strategy of C. morifolium. The chemical cue responsible for indirect defense in C. morifolium was identified as a complex blend of volatiles predominated by sesquiterpenes and monoterpenes. A total of 11 candidate terpene synthase (TPS) genes were identified by comparing the transcriptomes of healthy and TCW-infested plants. Gene expression analysis confirmed that up-regulated CmjTPS genes are consistent with the elevated emission of terpenes after herbivory treatment. Our study showed that the herbivore-induced emission of JA-dependent volatile terpenes attracted both predatory and parasitic enemies of herbivores. Generally, our findings indicate that indirect defense might be an important defense mechanism against insects in C. morifolium.

Nucleotides are the basic elements of the genetic material, participate in bio-energetic processes, are cofactors and components of secondary metabolites, etc. Nucleotide hydrolases (nucleotidases) are phosphatases that remove the 5'-phosphate group from the nucleotides and play a crucial role in nucleotide metabolism. In this study, genes encoding putative nucleotidases in Phaseolus vulgaris have been identified, and the effect of methyl jasmonate (MeJA) on both nucleotidase activity and gene expression has been addressed. The predicted nucleotidase peptides include the conserved domains characteristic of the haloacid dehalogenase-like hydrolase superfamily. The analysis of the expression of the 11 identified genes in radicles of common bean seedlings elicited with MeJA showed that 3 of them are highly induced by this phytohormone in a dose-dependent manner. Nucleotidase activity in radicles from MeJA treated plants was higher than in not elicited seedlings, and this induction was observed with all the nucleotides assayed (mono-, di- or triphosphate) and with purine or pyrimidine nucleotides. MeJA is involved in biotic and abiotic stress, and the induction of nucleotide metabolism in response to this treatment suggests a relevant role for nucleotides in the seedlings response to unfavourable conditions.

Cotton is an important fibre-producing crop. Cotton fibres consist of highly elongated trichomes derived from the ovule. To improve the quality of cotton, it is necessary to identify the genes regulating fibre development. GhMYB3 was identified through bioinfomatic analysis and introduced to Arabidopsis and cotton to observe the phenotype. Protein inteaction and promoter bingding assays were conducted to explore the role of GhMYB3 in trichome fibre growth. Cotton fibre development might share a similar regulatory mechanism to Arabidopsis leaf trichomes, which is determined by the essential regulatory complex, MYB-bHLH-WD40. The GL1-like R2R3 MYB transcription factor GhMYB3 interacts with the AtGL3 protein involved in Arabidopsis trichome development. Ectopic expression of GhMYB3 could rescue the glabrous phenotype of the Arabidopsis gl1 mutant and produced more ectopic trichomes on inflorescence stems and floral organs, confirming its orthologous function in plant trichome development. The expression of GhMYB3 increased in response to exogenous gibberellin (GA3 ), auxin (IAA) and methyl jasmonate (MeJA). Overexpression of this gene in cotton leads to a slight increase in fibre length and lint percentage, possibly by activating the transcription of its downstream gene GhRDL1 or other fibre-related genes. The results increase our understanding of the key role of GhMYB3 in positively controlling plant trichome development, and this gene could be a potential target for molecular breeding in cotton.

In vitro culture of Cynara cardunculus subsp. scolymus was induced from bracts and leaves, using different phytohormone combinations. The most suitable one was 1-naphthaleneacetic acid: 6-benzylami...

Co-culture of adventitious roots (ARs) of Echinacea purpurea (L.) Moench and E. pallida is a novel method for the production of Echinacea bioactive compounds. In the co-culture system, implementation of an elicitation strategy can likely promote bioactive compound accumulation in ARs. Therefore, in this work, methyl jasmonate (MeJA) was tested as an elicitor to treat 30-d-old bioreactor cultured ARs and the effect of MeJA concentrations on metabolite accumulation to select an optimal concentration of this elicitor. Furthermore, the antioxidant enzyme activities of ARs were also determined for understanding the mechanism of MeJA elicitation. Results showed that the 25 μM MeJA treatment increased metabolite accumulation in ARs with maximum production of phenolics (728.2 mg L−1), flavonoids (622.2 mg L−1), and caffeic acid derivatives (255.3 mg L−1 cichoric acid and 143.9 mg L−1 echinacoside); however, the highest polysaccharide production (approximately 440 mg L−1) was determined at 50 to 200 μM MeJA. The activities of antioxidant enzymes (superoxide dismutase, peroxidase, ascorbate peroxidase, and catalase) reached maximum levels with 25 μM MeJA, demonstrating a close relationship between antioxidant enzymes and secondary metabolite synthesis of co-cultured Echinacea ARs. In addition, the bioactive compound content in MeJA-treated ARs was compared with that in natural plant roots. The result indicated that the contents of phenolics, flavonoids, and caffeic acid derivatives (cichoric acid and echinocoside) were higher in the co-cultured ARs than in plant roots of E. purpurea and E. palida.

The ambrosia beetle Xylosandrus germanus (Blandford) is an invasive pest that has caused tree decline and death in numerous NY dwarf apple orchards during the past ten years, despite efforts to control them using trunk sprays of chlorpyrifos or pyrethroids, either alone or combined with the repellent verbenone. From 2017 to 2019, we tested trunk applications of different repellents and plant defense compounds for protection against X. germanus in potted apple trees adjacent to infested orchards. Treatments included topical formulations of verbenone and methyl salicylate (MeSa), alone and in combination, at different rates and timings. Additional treatments evaluated included the systemic acquired resistance activators acibenzolar-S-methyl, Reynoutria sachalinensis extract, and salicylic acid. The combination verbenone+MeSa treatments had the lowest incidences of attack sites and galleries containing adults or brood, although results varied among years. In a separate trial, we found no significant difference in numbers of adults caught in ethanol-baited traps placed 5–20 m from an apple bolt treated with the verbenone+MeSa repellent, suggesting that the repellent’s effect did not extend to those distances from the treated target. Cross-sectional discs of trunk tissue sampled in August were analyzed for levels of phytohormones. Quantities of ergosterol, abscissic acid, salicylic acid, jasmonic acid, methyl salicylate, methyl jasmonate, trans-cinnamic acid, and indole-3-cinnamic acid did not significantly vary across treatments; however, trees with greater beetle damage contained higher levels of jasmonic and salicylic acid, which are key molecules in plant defense pathways.

Introduction: Medicinal plants are being used to treat several diseases for many decades and this is an ancient method to treat the patients. Herbal plant Silybum marianum found most effective one to cure liver disorders. This plant produces silymarin which is a secondary metabolite and have hepatoprotective properties. Silymarin is a mixture of flavonolignans (silybin A, silybin B, isosilybin A isosilybin B, silychristin, silydianin apigenin 7-D glucose and taxifolin) that has antiviral, antibacterial, antifungal and antiallergenic properties. Therefore, the excessive production of silymarin is necessary to cure different types liver disorders, so the present study executed to boost up production of Silymarin flavonolignans in vegetative parts of the Silybum marianum plant by using different elicitors. Materials and Methods: In the present study, elicitation technique in hydroponics system was used to enhance the production of pharmacologically active flavonolignans in Silybum marianum. Fungal elicitors prepared from lyophilized Aspergillus niger biomass, methyl jasmonate, silver nanoparticles and combination of silver nanoparticles and methyl jasmonate were added (0.2g/l), (100µM/l), (1 ppm) and (100µM/lppm) in hydroponics with Hoagland’s solution in hydroponics to enhance the production of flavonolignans of Silybum marianum. Controls were also set for each treatment. Plants were harvested after 72 hours of introduction of elicitors. High performance liquid chromatography technique was used for analytical purpose. Four solvents (methanol, acetonitrile, chloroform and 2% Trifloro acetic acid) were used in HPLC. Column was C18 and run time of sample was 1 hour. Silybum marianum’s seed extract was used as a standard. Extract of control and treated plants were run on the same polarity in HPLC. Results: Results showed that after elicitation significant increase was observed in production of silymarin’s flavonolignans (silybin A, silybin B, isosilybin A, isosilybin B and apigenin 7-D glucose) in vegetative part of the plant but rate of production was different for each elicitor, fungal elicitors prepared from lyophilized Aspergillus niger biomass proved best among all treatments.

Background Andean lupin (Lupinus mutabilis Sweet) is an important leguminous crop from South America with a high protein content. In Ecuador, lupin yields are severely affected by the infestation of Delia platura larvae on germinating seeds. The application of elicitor molecules with activity against herbivorous insects to control Delia platura infestation constitutes an unexplored and promising alternative for chemical insecticides. In this study, Methyl Jasmonate (MeJA), Hexanoic acid (Hxa), Menadione Sodium Bisulfite (MSB), and DL-β-aminobutyric acid (BABA) were evaluated for their ability to induce resistance against D. platura in three commercial lupin cultivars. Results Only seeds pre-treated with MeJA significantly impaired insect performance during choice and no-choice assays. Additionally, fitness indicators such as seed germination and growth were not affected by MeJA treatment. To investigate the molecular mechanisms behind the MeJA-mediated resistance, RT-qPCR assays were performed. First, RT-qPCR reference genes were validated, showing that LmUBC was the most stable reference gene. Next, expression analysis over time revealed that MeJA application upregulated the activity of the Jasmonic Acid biosynthetic genes LmLOX2 and LmAOS, together with other jasmonate-related defense genes, such as LmTPS1, LmTPS4, LmPI2, LmMBL, LmL/ODC, LmCSD1, and LmPOD. Conclusion This study indicates that MeJA can be used as an environmentally friendly elicitor molecule to protect Andean lupin from D. platura attack without fitness cost. MeJA application induces plant defense responses to insects in Andean lupin that may be modulated by the onset of terpenoid biosynthesis, proteinase inhibitors, lectins, polyamines, and antioxidative enzymes. This article is protected by copyright. All rights reserved.

In this study, the effect of methyl jasmonate (MeJA) incorporation on in vitro propagation, metabolic profiling, and production of the bioactive compound, proximadiol, in the medicinally important herb Cymbopogon schoenanthus subsp. proximus has been investigated. The propagation approaches involved both somatic embryogenesis and direct organogenesis. All studied concentrations (10–400 µM) have significantly improved somatic embryogenesis at different developmental stages, as indicated by higher numbers of somatic and mature embryos as well as the embryogenic shoots. In contrast, the studied concentrations have negatively affected organogenic shoot and root regeneration. Metabolic profiling of polar extracts from the direct regenerated shoots was analyzed based on NMR measurements. The results showed that 200 µM MeJA increased production of trigonelline by tenfold. However, the concentrations of several amino acids including alanine were decreased. Based on gas chromatography and mass spectrometry (GC/MS) data, proximadiol concentrations significantly decreased with 10 and 100 µM MeJA. Proximadiol production improved by using 200 µM MeJA, although the data were non-significant. Our findings suggested that, while the addition of MeJA to embryogenic calli improved somatic embryo induction, maturation, and germination, it suppressed organogenic shoot and root formation. MeJA at a particular concentration (200 µM) enhanced the accumulation of trigonelline and osmoprotectant amino acids, while their effect on proximadiol production was statistically non-significant.

Coelogyne ovalis Lindl. is one of the important medicinal orchid, has been used in traditional medicines for the treatment of various human aliments. The therapetical uses of this orchid may be attributed to the presence of various secondary metabolites ultimately produced via the phenylpropanoid pathway. Amongst the various genes involved in phenylpropanoid pathway, chalcone synthase (CHS) deserves a special mention as it plays a pivotal role in the synthesis of secondary metabolites. In the present research, an attempt has been made to modulate the expressions of CHS transcript and subsequent enhancement in the production of secondary metabolites (phenolics, flavonoids and anthocyanins) and antioxidant activity by the application of biotic (chitosan and yeast extracts) and abiotic (salicylic acid, methyl jasmonate and abscisic acid) stresses to the in vitro-raised plantlets. Amongst the various stress factors taken into consideration, salicylic acid-treated leaves showed the highest tissue-specific expression pattern (13.53-fold at 50 μM), followed by methyl jasmonate (10.80-fold at 100 μM), chitosan (9.04-fold at 100 μM) as compared to control plantlets. The correlation between CHS expression and the presence of secondary metabolites was also studied to find out a suitable condition which would result in higher accumulation of secondary metabolites. Further, elicitations with best three stresses (namely salicylic acid, methyl jasmonate and chitosan) significantly modulated the accumulation of secondary metabolites. Deviations were also detected in terms of phytochemical contents; the salicylic acid-treated leaf tissues showed the highest contents of flavonoids (34.18 mg QE/gm DW) and anthocyanins (24.08 mg / gm FW) whereas phenolic contents were recorded to be highest in pseudobulbs (44.61 mg GAE/ gm DW). The plantlets treated with salicylic acid resulted in enhanced production of secondary metabolites and significantly higher antioxidant activity (DPPH and metal chelating). The present result suggests that stress stimulates CoCHS expression and secondary metabolites production in the treated tissues of C. ovalis.

Trigonella foenum-graecum L. is a widely used herb in traditional medicine. The aim of this study was to evaluate the genetic polymorphisms in fenugreek plants following the treatment of fenugreek seeds with different combinations of biotic and abiotic agents using the random amplified polymorphic DNA (RAPD)-PCR technique. We assessed the effects of two strains of the fungus Trichoderma harzianum (Th-1 and Th-2), methyl jasmonate (MeJA), and Aloe vera gel (AVG) on growth parameters of fenugreek plants. Combinations of Th-1, MeJA, AVG significantly increased fenugreek root length, shoot length, shoot fresh weight, number of true leaves, and chlorophyll content. The Th-2 isolate, on the other hand, markedly slowed plant development (except for root length which was not affected significantly). In contrast, the combination with MeJA had no considerable effect on all growth measures, whereas the combination with VAG resulted in a substantial drop in shoot height and chlorophyll content when compared to other growth parameters that were unaffected. The present study has shown that the PCR amplification of DNA, using five primers for RAPD analysis, produced 62 DNA fragments that could be scored in all genotypes. The total number of polymorphic bands was 26, and the average percentage of polymorphism was 54.21%. The RAPD-PCR results showed that the treatment of fenugreek seeds with Th-1 alone or in combination with MeJA and AVG induced polymorphisms in fenugreek leaves.

Digitalis purpurea L. is a perennial medicinal herb containing high concentrations of secondary metabolites like cardiac glycosides with extensive therapeutic use. This study aimed to evaluate the induction of secondary metabolites in D. purpurea by applying polyamines as elicitors in suspension cultures. Toward this aim, different explants of D. purpurea including leaf, petiole, and root were first cultured in MS30 medium, then, the potential of callus formation was investigated by applying 2,4-dichlorophenoxyacetic acid (2,4-D), benzylaminopurine (BAP), and naphthaleneacetic acid (NAA) hormones as inducers. The induction of secondary metabolites by different elicitors in suspension cell culture was assessed by applying 50 and 100 mg.L−1 of putrescine (PUT), spermidine (SPD), and spermine (SPM), and 50, 100, and 200 μM concentrations of Methyl jasmonate (MJ), respectively. All the experiments were performed as factorial in a completely randomized design (CRD) with three replications. Results showed that the application of hormone on leaf explants had a significant effect on callus induction. The highest fresh and dry weights of callus were obtained by leaf explant with 2 mg.L−1 BAP and 0.5 mg.L−1 2,4-D. Moreover, SPD and MJ significantly increased the phenol content, antioxidant activities, cardenolides, and digitoxin contents of the callus in suspension cell culture at the concentrations of 100 mg.L−1 and 50 µM, respectively in compared to control. Therefore, the application of SPD and MJ in suspension culture had an inhibitory and additive effect on the biosynthesis of secondary metabolites of D. purpurea.