Casteel Clare L, Yang Chunling, Nanduri Ananya C, De Jong Hannah N, Whitham Steven A, Jander Georg
Boyce Thompson Institute for Plant Research, Ithaca, NY, 14853, USA.
Plant J. 2014 Feb;77(4):653-63. doi: 10.1111/tpj.12417. Epub 2014 Jan 24.
Many plant viruses depend on aphids and other phloem-feeding insects for transmission within and among host plants. Thus, viruses may promote their own transmission by manipulating plant physiology to attract aphids and increase aphid reproduction. Consistent with this hypothesis, Myzus persicae (green peach aphids) prefer to settle on Nicotiana benthamiana infected with Turnip mosaic virus (TuMV) and fecundity on virus-infected N. benthamiana and Arabidopsis thaliana (Arabidopsis) is higher than on uninfected controls. TuMV infection suppresses callose deposition, an important plant defense, and increases the amount of free amino acids, the major source of nitrogen for aphids. To investigate the underlying molecular mechanisms of this phenomenon, 10 TuMV genes were over-expressed in plants to determine their effects on aphid reproduction. Production of a single TuMV protein, nuclear inclusion a-protease domain (NIa-Pro), increased M. persicae reproduction on both N. benthamiana and Arabidopsis. Similar to the effects that are observed during TuMV infection, NIa-Pro expression alone increased aphid arrestment, suppressed callose deposition and increased the abundance of free amino acids. Together, these results suggest a function for the TuMV NIa-Pro protein in manipulating the physiology of host plants. By attracting aphid vectors and promoting their reproduction, TuMV may influence plant-aphid interactions to promote its own transmission.
许多植物病毒依靠蚜虫和其他取食韧皮部的昆虫在寄主植物内部以及不同寄主植物之间传播。因此，病毒可能通过操控植物生理机能来吸引蚜虫并增加蚜虫繁殖，从而促进自身传播。与这一假说相符的是，桃蚜（烟蚜）更喜欢在感染了芜菁花叶病毒（TuMV）的本氏烟草上定居，并且在感染病毒的本氏烟草和拟南芥上的繁殖力高于未感染的对照植株。TuMV感染会抑制胼胝质沉积（一种重要的植物防御机制），并增加游离氨基酸的含量，而游离氨基酸是蚜虫氮的主要来源。为了探究这一现象背后的分子机制，在植物中过表达了10个TuMV基因，以确定它们对蚜虫繁殖的影响。单独一种TuMV蛋白，即核内含体a蛋白酶结构域（NIa-Pro）的产生，增加了桃蚜在本氏烟草和拟南芥上的繁殖。与TuMV感染期间观察到的效应相似，仅NIa-Pro的表达就增加了蚜虫的滞留，抑制了胼胝质沉积，并增加了游离氨基酸的丰度。这些结果共同表明TuMV NIa-Pro蛋白在操控寄主植物生理机能方面具有一种功能。通过吸引蚜虫媒介并促进其繁殖，TuMV可能影响植物与蚜虫的相互作用以促进自身传播。
