Induced Systemic Resistance against by AR156 through a JA/ET- and -Dependent Signaling Pathway and Activates PAMP-Triggered Immunity in .

Induced resistance response is a potent and cost effective plant defense against pathogen attack. The effectiveness and underlying mechanisms of the suppressive ability by AR156 to pv. DC3000 ( DC3000) in has been investigated previously; however, the strength of induced systemic resistance (ISR) activity against remains unknown. Here, we show that root-drench application of AR156 significantly reduces disease incidence through activation of ISR. This protection is accompanied with multilayered ISR defense response activated via enhanced accumulation of PR1 protein expression in a timely manner, hydrogen peroxide accumulation and callose deposition, which is significantly more intense in plants with both AR156 pretreatment and inoculation than that in plants with pathogen inoculation only. Moreover, AR156 can trigger ISR in and mutants, but not in and mutant plants. Our results indicate that AR156-induced ISR depends on JA/ET-signaling pathway and , but not SA. Also, AR156-treated plants are able to rapidly activate MAPK signaling and / gene expression, both of which are involved in pathogen associated molecular pattern (PAMP)-triggered immunity (PTI). The results indicate that AR156 can induce ISR by the JA/ET-signaling pathways in an -dependent manner and involves multiple PTI components.