OsGF14b modulates defense signaling pathways in rice panicle blast response

Rice with panicle-blast resistance is needed for stable rice production. Although we have previously demonstrated that OsGF14b underlies a quantitative trait locus that positively regulates rice panicle blast resistance, the mechanism is still unknown. In this study, a multi-omics approach was used to investigate the possible downstream signaling pathway regulated by OsGF14b. OsGF14b both strongly activated the gibberellin biosynthetic pathway during pathogen infection and reprogrammed the lignin biosynthetic pathway. Reduced lignin accumulation was observed in glumes of OsGF14b-overexpressing plants in comparison with the wild type after pathogen inoculation. OsGF14b activated the auxin and jasmonic acid signaling pathways, but inactivated the salicylic acid signaling pathway. Auxin and jasmonic acid appeared to act independently on OsGF14b-mediated panicle blast resistance. The roles of gibberellin, lignin, and auxin were different from their roles in leaf blast, suggesting that different mechanisms underlie leaf and panicle blast resistance in rice. This study provides a comprehensive catalog of molecular changes that could be targets for future studies of rice panicle blast resistance.