Jasmonate-Triggered Plant Immunity

Abstract

The plant hormone jasmonate (JA) exerts direct control over the production of chemical defense compounds that confer resistance to a remarkable spectrum of plant-associated organisms, ranging from microbial pathogens to vertebrate herbivores. The underlying mechanism of JA-triggered immunity (JATI) can be conceptualized as a multi-stage signal transduction cascade involving: i) pattern recognition receptors (PRRs) that couple the perception of danger signals to rapid synthesis of bioactive JA; ii) an evolutionarily conserved JA signaling module that links fluctuating JA levels to changes in the abundance of transcriptional repressor proteins; and iii) activation (de-repression) of transcription factors that orchestrate the expression of myriad chemical and morphological defense traits. Multiple negative feedback loops act in concert to restrain the duration and amplitude of defense responses, presumably to mitigate potential fitness costs of JATI. The convergence of diverse plant- and non-plant-derived signals on the core JA module indicates that JATI is a general response to perceived danger. However, the modular structure of JATI may accommodate attacker-specific defense responses through evolutionary innovation of PRRs (inputs) and defense traits (outputs). The efficacy of JATI as a defense strategy is highlighted by its capacity to shape natural populations of plant attackers, as well as the propensity of plant-associated organisms to subvert or otherwise manipulate JA signaling. As both a cellular hub for integrating informational cues from the environment and a common target of pathogen effectors, the core JA module provides a focal point for understanding immune system networks and the evolution of chemical diversity in the plant kingdom.

Venus flytrap carnivorous lifestyle builds on herbivore defense strategies

“…In response to insect attack, a traveling electrical wave translates into the rapid biosynthesis of JA (Mousavi et al 2013) and its receptor-active derivative jasmonoyl-L-isoleucine (JA-Ile) (Campos et al 2014). COI1-based perception of JA-Ile relieves JAZ proteinmediated negative transcriptional control, resulting in the production of secondary metabolites and proteins that exhibit well-known roles in defense.…”

“…In general, turning on defense is metabolically costly; it is frequently accompanied by significant growth inhibition and requires metabolic, transcriptional, and hormonal reprogramming (Yang et al 2012;Campos et al 2014). Initially, Dionaea invests energy in producing and growing traps and in providing the morphological and anatomical requirements for fast insect capture by storing elastic energy in a metastable configuration of the snap trap (Forterre et al 2005).…”

Defects in Peroxisomal 6-Phosphogluconate Dehydrogenase Isoform PGD2 Prevent Gametophytic Interaction in Arabidopsis thaliana

“…Therefore, it is conceivable that our findings have important implications for other plant species and conditions in which NO and/or JA act as signaling components: in the case of peroxisomal NO during abiotic stress in roots (Corpas et al, 2009;Corpas and Barroso, 2014a) and in the case of JA during herbivory/wounding or plant-pathogen interactions. The latter are accompanied by rapid stomata closure and the inhibition of photosynthesis (Katsir et al, 2008;Campos et al, 2014;Wasternack, 2014). In tobacco leaves, this leads to callose-induced Suc retention (source-to-sink transition), which is needed for the defense of the infected tissue (Scharte et al, 2009).…”

Quantitative Peptidomics Study Reveals That a Wound-Induced Peptide from PR-1 Regulates Immune Signaling in Tomato

“…It is expected that several signaling peptides are involved in combating herbivore and pathogen attack (Cheong et al, 2002;Francia et al, 2007;Chassot et al, 2008), but the details of the regulation of antiherbivore and antipathogen responses by peptides during wounding stress still await elucidation. Several DAMP peptides have been discovered in other plant species and suggested to be bioactive in tomato (Boller and Felix, 2009b;Campos et al, 2014); these include HypSys (Pearce et al, 2001a;Narvaez-Vasquez et al, 2007), RALF (Pearce et al, 2001b), and Pep1 (Huffaker et al, 2006;Trivilin et al, 2014). Pep1 was clearly identified to be pathogen related in Arabidopsis, and its putative precursor in tomato was recently found to involve in the antipathogen response (Trivilin et al, 2014).…”