Abstract:

Agrobacterium tumefaciens is a kind of gram-negative bacteria and present in soil. It can infect the wound parts of many varieties of dicotyledons, monocotyledons and gymnosperms, and induce the plant crown gall nodule by the product of vir genes located in the Ti plasmid. Thus, A. tumefaciens is an agricultural engineering bacterium, and has been widely used in plant genetic engineering. It has been shown that the expression of vir gene is regulated by VirA/VirG 2 component system. To summarize the molecular mechanism after A. tumefaciens infection, the paper expounds the structure and function of the VirA and VirG protein, and explains how the VirA/VirG two component system senses the environmental factors and how the expression of vir gene is regulated by these environmental factors through the VirA/VirG.

Key words: Agrobacterium tumefaciens, VirA/VirG two-component, vir gene expression, infection

摘要：

根瘤农杆菌（Agrobacterium tumefaciens）是存在于土壤中的革兰氏阴性菌，可以侵染很多种双子叶植物、单子叶植物以及裸子植物的受伤部位，用位于其Ti质粒上vir基因产物来诱导植物产生冠瘿瘤，因此，根瘤农杆菌广泛用于植物基因工程研究，是个农业工程菌。研究表明vir基因的表达受VirA/VirG二组分体的介导。回顾和总结了根瘤农杆菌的VirA/VirG二组分体的结构、作用机理、以及所感知的环境因子，和这些环境因子通过VirA/VirG二组分体对vir基因的表达调控分子机制。

关键词: 根瘤农杆菌;VirA/VirG二组分体:vir基因表达;侵染