大麦黄条点花叶病毒磷蛋白的致病机制分析

Rhabdoviruses comprises diverse members of negative-sense, single-stranded RNA viruses with broad host ranges including vertebrates, invertebrates and plants. The pathogenesis of plant rhabdoviruses are largely unknown due to the lack of infectious cDNA clones of plant rhabdoviruses. Barley yellow striate mosaic virus (BYSMV) is a world-wide cytorhabdovirus, and was recently reported to cause disease in the wheat field of North China. In our previous studies, the complete genome of BYSMV was obtained, and the minireplicon systems was successfully established. Based on these results, this proposal will focus on the pathogenic mechanisms of BYSMV P protein, a key determint factor of viral infection, through investigating the functional roles of its subcellular localization and phosphorylation modification, as well as the host-targeting proteins of BYSMV P. These results will provide new insights into understanding of the main functions of BYSMV P acting as accurate molecular targets for antiviral breeding, providing scientific bases for virus disease control.

弹状病毒属于单链负义RNA病毒，能够侵染脊椎动物、无脊椎动物以及植物等寄主。由于植物弹状病毒反向遗传学体系的缺乏，植物弹状病毒在寄主植物或介体昆虫体内的致病机制研究比较滞后。大麦黄条点花叶病毒(Barley yellow striate mosaic virus, BYSMV)是一种世界范围内广泛分布的植物细胞质弹状病毒，近期在我国北方小麦产区检测到该病毒病害的发生。本研究的前期工作首次报道BYSMV的全长基因组序列，并初步建立了病毒的微型复制子体系。在此基础上，本项目拟针对BYSMV的关键致病因子P蛋白的致病机制展开深入研究，分别从亚细胞定位和磷酸化氨基酸位点入手，逐步分析这些特征与寄主因子的互作关系，解析P蛋白在病毒致病过程中的关键作用，为抗病毒育种提供更精准的分子靶标，并为病毒病害的科学防治提供理论依据。

大麦黄条点花叶病毒(Barley yellow striate mosaic virus, BYSMV)属于细胞质弹状病毒, 侵染小麦、大麦、玉米等26种禾本科农作物，严重影响作物产量和品质。在此项目的资助下，我们主要对虫传植物弹状病毒―介体昆虫―寄主植物互作中的关键科学问题展开了系统研究。首先建立了BYSMV微型复制子体系和全长侵染性克隆体系，并开发了在单子叶植物和昆虫介体上高效的病毒表达载体；分析了植物寄主和昆虫介体内的CK1激酶磷酸化病毒磷蛋白(P)，并调控P相变过程，进而调控病毒复制和转录的转换过程；阐明了寄主RNA降解因子Carbon catabolite repression 4 (CCR4)被病毒劫持到病毒复合体中，促进病毒侵染的分子机制；最后鉴定了寄主MAPK激酶磷酸病毒核蛋白(N)，影响病毒复制复合体的组装过程。相关文章发表在Journal of Experimental Botany (2019)，New Phytologist (2019)，eLife (2020，2022)，和The Plant Cell (2020，2022)等高水平学术期刊上。此工作为抗病毒育种提供更精准的分子靶标，并为病毒病害的绿色防治提供理论依据。