Sulforaphane, a secondary metabolite in crucifers, inhibits the oxidative stress adaptation and virulence of Xanthomonas by directly targeting OxyR

作者：Bo Wang, Kaihuai Li, Guichun Wu, Zhizhou Xu, Rongxian Hou, Baodian Guo, Yancun Zhao, Fengquan Liu · 发表于：Molecular Plant Pathology · 年份：2022 · DOI：10.1111/mpp.13245 · 被引用次数：14 · 研究领域：Plant Pathogenic Bacteria Studies、Plant pathogens and resistance mechanisms、Plant-Microbe Interactions and Immunity

Plant secondary metabolites perform numerous functions in the interactions between plants and pathogens. However, little is known about the precise mechanisms underlying their contribution to the direct inhibition of pathogen growth and virulence in planta. Here, we show that the secondary metabolite sulforaphane (SFN) in crucifers inhibits the growth, virulence, and ability of Xanthomonas species to adapt to oxidative stress, which is essential for the successful infection of host plants by phytopathogens. The transcription of oxidative stress detoxification-related genes (catalase [katA and katG] and alkylhydroperoxide-NADPH oxidoreductase subunit C [ahpC]) was substantially inhibited by SFN in Xanthomonas campestris pv. campestris (Xcc), and this phenomenon was most obvious in sax gene mutants sensitive to SFN. By performing microscale thermophoresis (MST) and electrophoretic mobility shift assay (EMSA), we observed that SFN directly bound to the virulence-related redox-sensing transcription factor OxyR and weakened the ability of OxyR to bind to the promoters of oxidative stress detoxification-related genes. Collectively, these results illustrate that SFN directly targets OxyR to inhibit the bacterial adaptation to oxidative stress, thereby decreasing bacterial virulence. Interestingly, this phenomenon occurs in multiple Xanthomonas species. This study provides novel insights into the molecular mechanisms by which SFN limits Xanthomonas adaptation to oxidative stress and ...