Jasmonic acid elicits oxidative defense and detoxification systems in Cucumis melo L. cells

Abstract

This study investigated whether a jasmonic acid (JA) elicitation strategy developed in a conventional cell suspension culture could evoke melon resistance mechanisms, including secondary metabolite production. Twenty one day cultured melon cell suspensions grown in MS1 medium were supplemented with JA at the concentrations of 0.5, 5.0 and 10 µmol. Melon cultures were sampled 24, 48 and 72 h post elicitation to evaluate different defense related factors such as antioxidant enzymes, ascorbate metabolism and phenolic compounds. Results suggest that melon cells respond to JA reprogramming the primary and secondary metabolism which will result in melon plantlets with enhanced resistance against diverse stress conditions through the production of specific bioactive molecules. Jasmonic acid elicited melon cells exhibited enhanced oxidative enzymes activities and ascorbic acid, coumarin and p-coumaric amounts were found without growth retardation. Induced intracellular JA functions as a signal transducer acting upstream to H 2 O 2 , which is a secondary messenger triggering jasmonic signaling cascades by activating certain late genes that regulate the activity of catalase, peroxidase and de novo synthesis of five isozymes, ascorbic peroxidase detoxifying enzymes concomitant with ascorbate compound. Secondary metabolite production in melon cells seems to be activated upon JA exposure suggesting that this cell culture could be used as a source for rapid and increased production of coumarin, p-coumaric, ascorbic acid and likely other specific phenylpropanoids. These data provides further evidences for a role of jasmonic acid in the intracellular signal cascade that results in the accumulation of secondary compounds and ultimately induced melon resistance. This approach could assist further in understanding the metabolic mechanisms operating in melon cells under stress, and thus how to control them.

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

“…The p-coumaric acid content was higher in JA and SA treated plants than in the control plants. Nafie et al (2011) also noted an increase on caffeic and p-coumaric acid biosynthesis in melon cell cultures after stimulation with JA. Gentisic acid content was higher in JA (666.51 g/g), ABA (590.64 g/g), ETH (566.22 g/g) and SA (530.43 g/g) treated plants than in the control plants (514.15 g/g), and vanillin content was higher in the JA, ABA, SA and ETH treated plants than in the control plants (Table 1).…”

“…Secondary metabolite production is usually associated with rapid, transient increases in activities of key enzymes of the phenylpropanoid/flavonoid pathway such as PAL and chalcone isomerase (Nafie et al, 2011). In addition, many studies have shown that polyphenol oxidase is induced in response to the treatment with signaling molecules, such as JA/MJ and salicylic acid (Nafie et al, 2011). Twenty phenolic compounds, consisting of six hydroxybenzoic acid derivatives, five hydroxycinnamic acid derivatives, and nine flavonols were analyzed by UPLC ( Table 1).…”

Rhizobacteria induces resistance against Fusarium wilt of tomato by increasing the activity of defense enzymes

“…The Fusarium wilt severity was evaluated at 10, 15 and 25 days after inoculation (dai) using the scale proposed by De Cal et al (1995), where 1 = plant without symptoms, 2 = lower leaves yellowing, 3 = lower leaves dead and some upper leaves yellowing, 4 = lower leaves dead and some upper leaves wilting, and 5 = plant completely dead. The obtained scores were used to calculate the Fusarium wilt index (FWI) according to Mckinney (1923), consisting of the following: FWI=…”

“…Pruni interaction, a JA spray induced the expression of defense genes more than a salicylic acid spray (Sherif et al, 2012). The use of JA in melon cell cultures increased the endogenous level of this hormone and the activities of some defense enzymes (Nafie et al, 2011).…”

Antagonistic rhizobacteria and jasmonic acid induce resistance against tomato bacterial spot

“…Biological control and the application of resistance inducers may be a viable strategy for crops that do not have registered pesticides or for which registered products appear to be ineffective (Ferraz et al, 2014;Lanna et al, 2013;Shanmugam & Kanoujia, 2011). In this context, the utilization of resistance induced by non-pathogenic bacteria and abiotic inducers for disease control in agronomic crops has increased in recent years (Ferraz et al, 2014;Lanna et al, 2013;Nafie et al, 2011;Van Loon, 2007). In addition, there is an increasing demand by society for healthier food and less harm to the environment.…”