Fusarium sacchari is one of the primary pathogens causing pokkah boeng disease, which impairs the yield and quality of sugarcane around the world. Understanding the molecular mechanisms of the F. sacchari effectors that regulate plant immunity is of great importance for the development of novel strategies for the persistent control of pokkah boeng disease. In a previous study, Fs00367 was identified to inhibit BAX-induced cell death. In this study, Fs00367nsp (without signal peptide) was found to suppress BAX-induced cell death, reactive oxygen species bursts and callose accumulation. The amino acid region 113–142 of Fs00367nsp is the functional region. Gene mutagenesis indicated that Fs00367 is important for the full virulence of F. sacchari. A yeast two-hybrid assay revealed an interaction between Fs00367nsp and sugarcane ScPi21 in yeast that was further confirmed using bimolecular fluorescence complementation, pull-down assay and co-immunoprecipitation. ScPi21 can induce plant immunity, but this effect could be blunted by Fs00367nsp. These results suggest that Fs00367 is a core pathogenicity factor that suppresses plant immunity through inhibiting ScPi21-induced cell death. The findings of this study provide new insights into the molecular mechanisms of effectors in regulating plant immunity.

中文翻译：

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糖镰刀菌分泌的小效应蛋白通过抑制 ScPi21 诱导的细胞死亡来抑制宿主免疫反应

糖镰孢 (Fusarium sacchari)是引起 pokkah boeng 病的主要病原体之一，该病损害世界各地甘蔗的产量和质量。了解调节植物免疫的F. sacchari效应子的分子机制对于开发持久控制 pokkah boeng 病的新策略非常重要。在之前的一项研究中，Fs00367被确定可以抑制 BAX 诱导的细胞死亡。在这项研究中，发现 Fs00367nsp（不含信号肽）可抑制 BAX 诱导的细胞死亡、活性氧爆发和胼胝质积累。Fs00367nsp 的氨基酸区 113-142 是功能区。基因突变表明Fs00367对于糖镰孢的完全毒力非常重要。酵母双杂交测定揭示了酵母中 Fs00367nsp 和甘蔗 ScPi21 之间的相互作用，并使用双分子荧光互补、pull-down 测定和免疫共沉淀进一步证实了这一相互作用。ScPi21可以诱导植物免疫，但这种效果可能会被Fs00367 nsp削弱。这些结果表明Fs00367是一个核心致病因子，通过抑制ScPi21诱导的细胞死亡来抑制植物免疫。这项研究的结果为调节植物免疫效应的分子机制提供了新的见解。