Abah Felix, Zheng Qiaojia, Chen Xinru, Huang Linwan, Chen Xiaomin, Biregeya Jules, Aron Osakina, Wang Zonghua, Tang Wei
State Key Laboratory of Agricultural and Forestry Biosecurity, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China.
Fujian Universities Key Laboratory for Plant-Microbe Interaction, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, China.
PLoS Pathog. 2025 Jul 28;21(7):e1013011. doi: 10.1371/journal.ppat.1013011. eCollection 2025 Jul.
Rice (Oryza sativa L.) is one of the most important staple foods for human population worldwide. However, rice production continues to be severely threatened by rice blast disease caused by an ascomycete fungus Magnaporthe oryzae. Tail-anchored (TA) proteins are conserved across diverse organisms and belong to a class of polypeptides that are inserted into the membrane by a hydrophobic sequence located at the C-terminal region. The Guided Entry of Tail-anchored (GET) complex is responsible for the post-translational insertion of nascent TA proteins into the Saccharomyces cerevisiae ER lipid bilayer. In S. cerevisiae, the GET pathway comprises six known associated components Get1, Get2, Get3, Get4, Get5, Sgt2 and Ssa1 that have been identified and extensively studied. However, the role of the GET complex in rice blast fungus has not been elucidated. Here, we identified five proteins of the GET Complex in M. oryzae, namely MoGet1, MoGet2, MoGet3, MoGet4 and MoSgt2 and generated the gene knock-out mutants. Deletion of MoGET1 and MoGET2 revealed that they are required for vegetative growth, asexual reproduction, pathogenesis, and right localization of TA protein, MoYsy6, while MoGet3 negatively regulates hyphal growth, asexual development and pathogenesis of M. oryzae. In contrast, loss of MoGet4 and MoSgt2 had no effect on the normal development of the rice blast fungus. We demonstrated that the MoGet2 is important in osmotic stress response and positively regulates cell wall integrity. The MoGet1 and MoGet2 were ER-localized and indispensable for DTT-induced ER stress response. In vitro and in vivo interaction assay revealed MoGet3 has physical interaction with both MoGet1 and MoGet2, indicating the existence of a possible synergistic function amongst the Get components in rice blast fungus. In summary, this finding provides valuable insight into the biological functions of the GET components in plant fungal pathogens.
水稻（Oryza sativa L.）是全球人类最重要的主食之一。然而，水稻生产仍受到子囊菌Magnaporthe oryzae引起的稻瘟病的严重威胁。尾锚定（TA）蛋白在不同生物体中保守，属于一类通过位于C端区域的疏水序列插入膜中的多肽。尾锚定蛋白的引导进入（GET）复合体负责将新生的TA蛋白翻译后插入酿酒酵母内质网脂质双层。在酿酒酵母中，GET途径包含六个已鉴定并广泛研究的已知相关组分Get1、Get2、Get3、Get4、Get5、Sgt2和Ssa1。然而，GET复合体在稻瘟病菌中的作用尚未阐明。在此，我们在稻瘟病菌中鉴定出GET复合体的五个蛋白，即MoGet1、MoGet2、MoGet3、MoGet4和MoSgt2，并构建了基因敲除突变体。MoGET1和MoGET2的缺失表明它们对于营养生长、无性繁殖、致病性以及TA蛋白MoYsy6的正确定位是必需的，而MoGet3负向调节稻瘟病菌的菌丝生长、无性发育和致病性。相反，MoGet4和MoSgt2的缺失对稻瘟病菌的正常发育没有影响。我们证明MoGet2在渗透胁迫应答中很重要，并正向调节细胞壁完整性。MoGet1和MoGet2定位于内质网，对于二硫苏糖醇（DTT）诱导的内质网应激反应不可或缺。体外和体内相互作用分析表明MoGet3与MoGet1和MoGet2都存在物理相互作用，表明稻瘟病菌中Get组分之间可能存在协同功能。总之，这一发现为植物真菌病原体中GET组分的生物学功能提供了有价值的见解。
