Spodoptera litura-mediated chemical defense is differentially modulated in older and younger systemic leaves of Solanum lycopersicum

Abstract

Metabolite profiling, biochemical assays, and transcript analysis revealed differential modulation of specific induced defense responses in local, older, and younger systemic leaves in Solanum lycopersicum upon Spodoptera litura herbivory. Plants reconfigure their metabolome upon herbivory to induce production of defense metabolites involved in both direct and indirect defenses against insect herbivores. Herbivory mediated leaf-to-leaf systemic induction pattern of primary and non-volatile secondary metabolites is not well studied in tomato. Here, we show that, in cultivated tomato Solanum lycopersicum herbivory by generalist insect, Spodoptera litura results in differential alteration of primary metabolites, majorly sugars and amino acids and specific secondary metabolites in local, younger, and older systemic leaves. Cluster analysis of 55 metabolites identified by GC-MS showed correlation between local and younger systemic leaves. Re-allocation of primary metabolites like glucose and amino acids from the local to systemic leaf was observed. Secondary metabolites chlorogenic acid, caffeic acid, and catechin were significantly induced during herbivory in systemic leaves. Among specific secondary metabolites, chlorogenic acid and catechin significantly inhibits S. litura larval growth in all stages. Local leaf exhibited increased lignin accumulation upon herbivory. Differential alteration of induced defense responses like reactive oxygen species, polyphenol oxidase activity, proteinase inhibitor, cell wall metabolites, and lignin accumulation was observed in systemic leaves. The metabolite alteration also resulted in increased defense in systemic leaves. Thus, comparative analysis of metabolites in local and systemic leaves of tomato revealed a constant re-allocation of primary metabolites to systemic leaves and differential induction of secondary metabolites and induced defenses upon herbivory.

Site-dependent induction of jasmonic acid-associated chemical defenses against western flower thrips in Chrysanthemum

“…2d). Systemic defense responses are often found to be highly variable in space and time, and many studies have reported differences in local and systemic defense responses to herbivory or exogenous hormone application (Babst et al 2009;Moreira et al 2009;Lee et al 2017;Kundu et al 2018). Systemically induced resistance can be achieved by the systemic transport, through the plant vascular system, of defensive metabolites and/or signals from the induced tissues that activate de novo expression of resistance-associated traits (Heil and Ton 2008).…”

In silico identification of effector proteins from generalist herbivore Spodoptera litura

“…is NBAII–MP-NOC-02). After hatching, larvae (50) were reared on gram flour-based artificial diet at 25 ± 2 °C with 8 h /16 h of the light-dark period [ 59 ]. For Arabidopsis fed S. litura, the insects (50) were allowed to feed on 5–6 week old Arabidopsis plants for 24 h prior to gland isolation.…”

Roots drive oligogalacturonide-induced systemic immunity in tomato

“…This would provide plants with a mechanism to fine-tune defence responses according to the damaged organ. The observation that systemic responses are stronger than local ones in both roots and shoots suggests that plants invest more resources in preparing distal tissues for efficient defence activation against a potential upcoming attack (Gomez et al, 2010;Steinbrenner et al, 2011;Kundu et al, 2018).…”