Manipulation of plant defenses by an insect-vectored virus

某些植物致病性病毒的感染不仅使寄主植物对蚜虫更具吸引力，而且提高了蚜虫的生长和繁殖速度。这可能代表病毒对植物代谢的主动操纵，病毒依靠昆虫从一株植物传播到另一株植物。然而，尽管许多研究表明蚜虫在受病毒感染的植物上生长发生了改变，但人们对这种现象背后的分子机制知之甚少。以拟南芥（Arabidopsis thaliana）、桃蚜（Myzus persicae）和芜菁花叶病毒（TuMV）为模型系统，研究植物-蚜虫-病毒相互作用的分子生物学。初步结果表明，在受tumv感染的植物中，通常在蚜虫开始摄食时开启的拟南芥防御反应减少了。进一步的研究将针对测量病毒诱导的植物代谢变化，确定由TuMV操纵的植物防御途径，并确定在拟南芥和其他植物物种中关闭抗蚜虫防御所需的11个TuMV基因中的哪一个。TuMV是蔬菜作物的一种严重病原菌，通常由青桃蚜虫传播。由于桃薯蚜虫产生杀虫剂抗性的倾向，以及拟南芥和其他杂草物种中的TuMV储存库，农业系统中的病毒控制变得复杂。对拟南芥、桃子-马铃薯蚜虫和TuMV相互作用的研究，将发现植物代谢中以前未知的方面，这些方面有助于蚜虫的吸引和繁殖。这些信息可用于通过传统育种和转基因方法提高作物的抗虫和抗病毒能力。该计划还将有助于培养植物分子生物学、生物化学和遗传学方面的新一代学生。这些学生将为将来从事植物生物技术行业、学术界或政府服务做好充分的准备。

Infections with some plant-pathogenic viruses not only make the host plants more attractive for aphids, but also increase the rate of aphid growth and reproduction. This may represent active manipulation of plant metabolism by viruses, which rely on insects for their transmission from one plant to another. However, although numerous studies have demonstrated altered aphid growth on virus-infected plants, very little is known about the molecular mechanisms that underlie this phenomenon. Research using Arabidopsis thaliana (Arabidopsis), Myzus persicae (peach-potato aphid), and Turnip mosaic virus (TuMV) as a model system will be used to study the molecular biology of plant-aphid-virus interactions. Preliminary results show that Arabidopsis defense responses, which are normally turned on when aphids initiate feeding, are reduced in TuMV-infected plants. Further research will be directed at measuring virus-induced changes in plant metabolisms, identifying plant defense pathways that are manipulated by TuMV, and determining which of the eleven TuMV genes are required for shutting down anti-aphid defenses in Arabidopsis and other plant species.TuMV, which is commonly transmitted by green peach aphids, is a serious pathogen of vegetable crops. Virus control in agricultural systems is complicated by the propensity of peach-potato aphids to develop insecticide resistance, as well as TuMV reservoirs in Arabidopsis and other weed species. Research on the interactions of Arabidopsis, peach-potato aphids, and TuMV interactions, will identify previously unknown aspects of plant metabolism that contribute to aphid attraction and reproduction. Such information can be used to improve the insect and virus resistance of crop plants through classical breeding and transgenic approaches. The proposed project also will contribute to training a new generation of students in plant molecular biology, biochemistry, and genetics. These students will be well-prepared for future careers in the plant biotechnology industry, academia, or government service.