Auxilin-like蛋白MoSwa2在稻瘟病菌致病过程中的功能分析

Rice blast is a destructive disease on rice, threatening global food security. When Magnaporthe oryzae interacts with rice, it secretes a large number of effectors that interfere with the immune response of rice, which depends on the vesicle transport process, but the mechanism is still unclear. Previous studies by the applicant's team found that Actin regulating kinase MoArk1 mediates the transport of vesicle proteins, coordinates endocytosis and secretion, and controls virulence. In order to further study the mechanism of MoArk1 in vesicle transport, the applicant identified a MoArk1 interacting protein MoSwa2 by immunoprecipitation. The pathogenicity of the MoSWA2 gene knock-out mutant was significantly reduced, and a large amount of reactive oxygen species was accumulated in the host cells, suggesting that the mutant could not inhibit the host immune response. This project will further study the mechanism of MoSwa2 regulating secretion and intracellular protein transport, and identify the effectors regulated by MoSwa2, so as to elucidate its molecular mechanism of interfering with host immune response. The development of this work not only helps to understand the pathogenic mechanism of M.oryzae, but also has important reference value for understanding the pathogenic mechanism of other plant pathogenic fungi.

稻瘟病是水稻上的毁灭性病害，威胁着全球粮食安全。该病菌与水稻互作时，分泌大量的效应子干扰水稻的免疫反应，该过程依赖于囊泡的运输过程，但是其机制仍不十分清楚。申请者所在课题组前期研究发现Actin调控激酶MoArk1调控囊泡蛋白转运，协调胞吞和外泌，控制致病力。为了进一步研究MoArk1在囊泡转运中的作用机制，申请者通过免疫共沉淀的方法，鉴定到与其互作的MoSwa2蛋白。该蛋白编码基因敲除后致病力显著降低，且寄主细胞中积累大量活性氧，提示该突变体无法抑制寄主免疫反应。本项目将深入研究MoSwa2调控外泌及胞内蛋白转运的机制，并鉴定受MoSwa2调控的外泌效应分子，从而解析其抑制寄主免疫反应的分子机制。该工作的开展，不仅有助于认识该病菌的致病机理，同时对解析其他植物病原真菌的致病机制具有重要参考价值。

稻瘟病是水稻上的毁灭性病害，威胁着全球粮食安全。该病菌与水稻互作时，分泌大量的效应子干扰水稻的免疫反应，该过程依赖于囊泡的运输过程，但是其机制仍不十分清楚。申请者所在课题组前期研究发现Actin调控激酶MoArk1调控囊泡蛋白转运，协调胞吞和外泌，控制致病力。为了进一步研究MoArk1在囊泡转运中的作用机制，本项目通过免疫共沉淀的方法，鉴定到与其互作的MoSwa2蛋白。发现该蛋白编码基因敲除后致病力显著降低，且寄主细胞中积累大量活性氧，提示该突变体无法抑制寄主免疫反应。本项目研究揭示了稻瘟病菌囊泡解聚因子MoSwa2与COPII组分蛋白MoSec24互作共同调控COPII囊泡的解聚，促进效应子蛋白的分泌，从而抑制寄主的免疫反应，帮助稻瘟病菌侵染水稻。该工作的完成，不仅阐明病原菌通过囊泡运输调控效应子分泌的机理，同时揭示了稻瘟病菌与水稻互作的分子机理，对基于稻瘟病菌致病机制的新型靶标的发掘具有重要参考价值。