内质网蛋白MoPer1及其互作蛋白调控稻瘟病菌生长发育和致病的分子机制研究

Filamentous fungal cell wall plays an essential role in maintaining hyphal morphology and adaptation to the environment. GPI-anchoring is a prevalent Glycosylphosphatidylinositol modification process of posttranslational protein and is necessary for cell wall integrity in eukaryotes. To date, the process and function of GPI anchored-related protein is still not known in phytopathogenic fungi. Here, we use genetics means to obtain the deletion mutant of MoPER1 that plays an important role in lipid remodeling of GPI-anchored proteins, and examine a series of biological phenotypes including cell wall integrity, growth, development, appressorium formation and pathogenicity. Furthermore, we identify the interactional protein of MoPer1 and elucidate the biological functions of one or two interactional proteins. The results will help to deep elucidate the molecular mechanism of cell wall integrity regulated by GPI-anchored-related protein MoPer1 and its interactional proteins during growth, development and pathogenicity of M. oryzae, and provide new clue for developing effective fungicide targeting genes regulation network involved in cell wall integrity to prevent the disease.

丝状真菌细胞壁对维持其菌丝的正常形态以及适应环境具有非常重要的作用。GPI锚定是细胞壁蛋白转录翻译后糖基化磷脂酰肌醇修饰过程，在真核生物中这一过程非常普遍，且对于细胞壁的完整性是必需的，但是GPI锚定相关蛋白在植物病原真菌中的功能以及作用机制仍不清楚。本研究拟采用遗传学手段获得GPI锚定蛋白脂质重构过程中的关键基因MoPER1的敲除突变体，测定突变体细胞壁的完整性、生长发育、附着胞形成及致病性等生物学表型；进一步鉴定MoPer1互作蛋白，研究1-2个互作蛋白在稻瘟病菌细胞壁完整性、生长发育和致病中的作用。研究结果有助于阐明该GPI锚定相关的MoPer1及其互作蛋白调控的细胞壁完整性在稻瘟病菌发育、产孢及致病相关过程中的分子作用机制，同时为开发以调控细胞壁完整性的基因网络为靶标的防治稻瘟病的新型药剂提供新的线索。

GPI锚定是细胞壁蛋白翻译后普遍存在的糖基磷脂酰肌醇修饰过程，并且在真核生物中对于细胞壁完整性所必需的。 迄今为止，GPI锚定相关蛋白的功能在植物致病真菌中仍然未知。.我们在这个课题了阐明了MoPer1的功能，MoPer1是稻瘟病菌Magnaporthe oryzae中与酿酒酵母ScPer1同源的蛋白。 转录分析表明MoPER1在分生孢子和感染过程中显着上调。 我们发现ΔMoper1突变体在分生孢子和附着胞形成方面存在缺陷，MoPer1参与渗透胁迫反应并维持细胞壁完整性。 致病性测定表明MoPEP1基因的缺失显着降低了致病力。显微镜观测显示ΔMoper1突变体的侵染菌丝主要限于最初感染的叶鞘细胞内。.我们的结果表明MoPer1对于稻瘟病菌的生长，分生孢子形成和致病性是必需的。 本研究有助于深入阐明稻瘟病菌的致病分子机制，为开发以基因为靶标的高效杀菌剂提供了有益的参考价值。