A role for β‐sitosterol to stigmasterol conversion in plant–pathogen interactions

摘要: Upon inoculation with pathogenic microbes, plants induce an array of metabolic changes that potentially contribute to induced resistance or even enhance susceptibility. When analysing leaf lipid composition during the Arabidopsis thaliana-Pseudomonas syringae interaction, we found accumulation phytosterol stigmasterol is a significant plant process occurs upon bacterial infection. Stigmasterol synthesized from beta-sitosterol by cytochrome P450 CYP710A1 via C22 desaturation. cyp710A1 mutant lines impaired in pathogen-inducible expression desaturase and concomitant are more resistant both avirulent virulent P. strains than wild-type plants, exogenous application attenuates this phenotype. These data indicate sterol desaturation favours pathogen multiplication formation triggered through perception pathogen-associated molecular patterns such as flagellin lipopolysaccharides, production reactive oxygen species, but does not depend on salicylic acid, jasmonic acid ethylene defence pathways. Isolated microsomal plasma membrane preparations exhibited similar increase stigmasterol/beta-sitosterol ratio whole-leaf extracts after syringae, indicating produced incorporated into membranes. The increased contents leaves attack do influence acid-mediated signalling attenuate pathogen-induced regulator flavin-dependent monooxygenase 1. thus promotes disease susceptibility stimulation leaves, which increases