植物抗病毒侵染的分子机制  

Molecular Mechanism of Plant Defense against Virus Attack

作　　者：侯静[1] 刘青青[1] 徐明良[1] 

机构地区：[1]中国农业大学/国家玉米改良中心,北京100193

出　　处：《作物学报》2012年第5期761-772,共12页Acta Agronomica Sinica

基　　金：国家重点基础研究发展计划(973计划)项目(2009CB118401)资助

摘　　要：植物病毒病是一类严重危害农作物生产的重要病害。已报道的植物抗病毒基因主要在抑制病毒增殖和阻止病毒扩散中起作用。病毒的复制涉及自身的编码蛋白及其与寄主蛋白间的互作,参与病毒复制的寄主蛋白很多,如真核翻译起始因子eIF4E和eIF4G,植物的内膜系统等,相关蛋白的功能丧失或构型改变可阻滞病毒的复制;此外,植物细胞内的硫氧还蛋白可调节细胞的氧化还原状态,进而阻断病毒的增殖。病毒在植物体内的扩散包括胞间移动和长距离迁移,植物抗病蛋白(R蛋白)通过识别病毒的无毒因子(Avr)促发防御反应,诱导过敏性坏死,限制病毒在细胞间的扩散,编码这类抗病蛋白的基因主要为TIR-NBS-LRR和CC-NBS-LRR。病毒的长距离迁移涉及的因素很多,目前仅发现韧皮部的RTM蛋白可能以多聚蛋白的形式抵制病毒的长距离移动。另外,RNA沉默也是植物抵制病毒侵染的免疫反应机制。本文旨在综述植物的各种抗病毒机制和相关的抗病基因,并探讨分子标记辅助选择(marker-assisted selection,MAS)、定向诱导基因组局部突变(targeting induced local lesions in genomes,TILLING)和转基因等生物技术在抗病改良中的应用前景。Viral diseases of plants seriously threaten the crop productivity. Many virus resistance genes are reported to play roles in restraining viral replication and preventing virus movement. The viral replication is a complex process which depends on virus-encoded proteins, host factors, and their interactions. Many host factors are actively engaged in viral replication, e.g. eukaryotic translation initiation factor 4E （eIF4E） and 4G （eIF4G）, and plant endomembrane systems. The loss-of-function or conformational changes of these host factors may inhibit viral replication. Furthermore, thioredoxin can regulate cellular redox state to restrain viral replication. Virus movement involves cell-to-cell movement and long distance movement. Hypersensitive cell death is trigged through the perception of a pathogen avirulence factor （Avr） by the cognate plant resistance protein （R protein） to limit the viral cell to cell movement. Dominant plant R genes, characterized by TIR-NBS-LRR or CC-NBS-LRR, are generally responsible for such kind of defense response. There are many factors associated with the long distance virus movement, but only polymerized RTM protein in phloem was identified to limit viral long distance movement. In addition, RNA silencing also actively functions as an antiviral defense response. This review is aimed to summarize various mechanisms of plant defense against virus attack, and to analyze possible implementations of MAS, TILLING, and transgenic technologies in the improvement of virus disease resistance in crops.

关 键 词：植物 病毒 基因 抗病蛋白 Avr因子 RNA沉默 

分 类 号：S432.2[农业科学—植物病理学]