Pseudomonas syringae type III effector AvrRpt2 alters Arabidopsis thaliana auxin physiology
Pseudomonas syringae type III effector AvrRpt2 alters Arabidopsis thaliana auxin physiology
复制标题
DOI：
10.1073/pnas.0704901104
复制
发表时间：
2007-12-11
影响因子：
11.1
通讯作者：
Kunkel, Barbara N.
中科院分区：
文献类型：
--
作者：
Chen, Zhongying;Agnew, Jennifer L.;Kunkel, Barbara N.
假单胞菌III型效应子AvrRpt 2促进缺乏功能性RPS 2基因的拟南芥植物（rps 2突变体植物）上的细菌毒力。为了研究AvrRpt 2毒力活性的潜在机制，我们检测了转基因A.组成型表达AvrRpt 2的拟南芥rps 2幼苗。这些幼苗表现出类似A.生长素生理学改变的拟南芥突变体，包括更长的主根，侧根数量增加，和对外源生长素的敏感性增加。他们还增加了游离吲哚乙酸（IAA）的水平。AvrRpt 2的存在也与进一步增加游离IAA水平在感染期间与A purigae pv.番茄菌株DC 3000（PstDC 3000）。这些结果表明AvrRpt 2改变了A.拟南芥生长素生理学生长素类似物1-萘乙酸的应用促进了PstDC 3000感染植物的疾病症状的发展，表明宿主组织内生长素水平的升高促进了PstDC 3000的毒力。因此，AvrRpt 2可能是调节宿主生长素生理以促进疾病的A.
The Pseudomonas syringae type III effector AvrRpt2 promotes bacterial virulence on Arabidopsis thaliana plants lacking a functional RPS2 gene (rps2 mutant plants). To investigate the mechanisms underlying the virulence activity of AvrRpt2, we examined the phenotypes of transgenic A. thaliana rps2 seedlings constitutively expressing AvrRpt2. These seedlings exhibited phenotypes reminiscent of A. thaliana mutants with altered auxin physiology, including longer primary roots, increased number of lateral roots, and increased sensitivity to exogenous auxin. They also had increased levels of free indole acetic acid (IAA). The presence of AvrRpt2 also was correlated with a further increase in free IAA levels during infection with A syringae pv. tomato strain DC3000 (PstDC3000). These results indicate that AvrRpt2 alters A. thaliana auxin physiology. Application of the auxin analog 1-naphthalene-acetic acid promoted disease symptom development in PstDC3000-infected plants, suggesting that elevated auxin levels within host tissue promote PstDC3000 virulence. Thus, AvrRpt2 may be among the virulence factors of A syringae that modulate host auxin physiology to promote disease.