Insights into the role of jasmonic acid-mediated defenses against necrotrophic and biotrophic fungal pathogens

Jasmonic acid (JA) is a natural hormone regulator involved in development, responses against wounding and pathogen attack. Upon perception of pathogens, JA is synthesized and mediates a signaling cascade initiating various defense responses. Traditionally, necrotrophic fungi have been shown to be the primary activators of JAdependent defenses through the JA-receptor, COI1. Conversely, plants infected with biotrophic fungi have classically been associated with suppressing JA-mediated responses. However, recent evidence has shown that certain biotrophic fungal species also trigger activation of JA-mediated responses and mutants deficient in JA signaling show an increase in susceptibility to certain biotrophic fungal pathogens. These findings suggest a new role for JA in defense against fungal biotrophs. This review will focus on recent research advancing our knowledge of JA-dependant responses involved in defense against both biotrophic and necrotrophic fungi.