Jasmonate regulates plant resistance to by inducing indole glucosinolate biosynthesis.

() is a necrotrophic bacterium that causes the soft rot disease in . However, the mechanisms underlying plant immune responses against necrotrophic bacterial pathogens with a broad host range are still not well understood. Using a flg22-triggered seedling growth inhibition (SGI) assay with 455 inbred lines, we selected six flagellin-insensitive lines (fin2-7) and three flagellin-sensitive lines (fs1-3). fin lines showed compromised flg22-induced immune responses (oxidative burst, mitogen-activated protein kinase (MAPK) activation, and seedling growth inhibition) compared to the control line R-o-18; nevertheless, they were resistant to . To explain this, we analyzed the phytohormone content and found that most fin lines had higher -induced jasmonic acid (JA) than fs lines. Moreover, MeJA pretreatment enhanced the resistance of to . To explain the correlation between the resistance of fin lines to and activated JA signaling, we analyzed pathogen-induced glucosinolate (GS) content in . Notably, in fin7, the neoglucobrassicin (NGBS) content among indole glucosinolates (IGS) was significantly higher than that in fs2 following inoculation, and genes involved in IGSs biosynthesis were also highly expressed. Furthermore, almost all fin lines with high JA levels and resistance to had higher -induced NGBS levels than fs lines. Thus, our results show that activated JA-mediated signaling attenuates flg22-triggered immunity but enhances resistance to by inducing indole glucosinolate biosynthesis in . This study provides novel insights into the role of JA-mediated defense against necrotrophic bacterial pathogens within a broad host range.