A Pseudomonas syringae pv. tomato DC3000 mutant lacking the type III effector HopQ1-1 is able to cause disease in the model plant Nicotiana benthamiana
A Pseudomonas syringae pv. tomato DC3000 mutant lacking the type III effector HopQ1-1 is able to cause disease in the model plant Nicotiana benthamiana
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DOI：
10.1111/j.1365-313x.2007.03126.x
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发表时间：
2007-07-01
期刊：
影响因子：
7.2
通讯作者：
Collmer, Alan
中科院分区：
文献类型：
--
作者：
Wei, Chia-Fong;Kvitko, Brian H.;Collmer, Alan
模式病原菌为假单胞菌烟草致病变种（Pseudomonaserichiningaepv.）番茄DC3000在番茄和拟南芥中引起细菌性斑点病，但重要的模式植物本氏烟草（Nicotianabenthamiana）被认为是非寄主。菌株DC3000通过III型分泌系统（T3SS）将大约28种效应蛋白注入植物细胞。这些蛋白质被单独递送到N.在该试验中，包括HopQ1 - 1在内的8个菌株显示出一定的导致细胞死亡的能力。从DC 3000中删除了编码13个效应子的四个基因簇：簇II（hopH 1、hopC 1）、IV（hopD 1、hopQ 1 - 1、hopR 1）、IX（hopAA 1 - 2、hopV 1、hopAO 1、hopG 1）和天然质粒pDC 3000 A（hopAM 1 - 2、hopX 1、hopO 1 - 1、hopT 1 - 1）。缺失簇IV或仅缺失hopQ1 - 1的DC3000突变体获得了在N.本萨米亚纳HopQ1 - 1在N. benthamiana：在烟草野火病原体P. tabaci11528使该菌株在N. benthamiana的过敏反应，以及引起N. HopQ1 - 1对本氏菌的作用依赖于SGT1。在hopQ1 - 1缺陷背景下，涉及其他效应基因簇的DC3000多突变体揭示了簇II和IX有助于N. benthamiana，以及拟南芥和番茄。这些结果支持了这一假设，即P.erichingae致病变种的寄主范围受到效应子库与植物抗效应子监视系统的复杂相互作用的限制，并且它们证明了N.本氏藻是DC3000的一种有用的模式寄主。
The model pathogen Pseudomonas syringae pv. tomato DC3000 causes bacterial speck in tomato and Arabidopsis, but Nicotiana benthamiana, an important model plant, is considered to be a non-host. Strain DC3000 injects approximately 28 effector proteins into plant cells via the type III secretion system (T3SS). These proteins were individually delivered into N. benthamiana leaf cells via T3SS-proficient Pseudomonas fluorescens, and eight, including HopQ1-1, showed some capacity to cause cell death in this test. Four gene clusters encoding 13 effectors were deleted from DC3000: cluster II (hopH1, hopC1), IV (hopD1, hopQ1-1, hopR1), IX (hopAA1-2, hopV1, hopAO1, hopG1), and native plasmid pDC3000A (hopAM1-2, hopX1, hopO1-1, hopT1-1). DC3000 mutants deleted for cluster IV or just hopQ1-1 acquired the ability to grow to high levels and produce bacterial speck lesions in N. benthamiana. HopQ1-1 showed other hallmarks of an avirulence determinant in N. benthamiana: expression in the tobacco wildfire pathogen P. syringae pv. tabaci 11528 rendered this strain avirulent in N. benthamiana, and elicitation of the hypersensitive response in N. benthamiana by HopQ1-1 was dependent on SGT1. DC3000 polymutants involving other effector gene clusters in a hopQ1-1-deficient background revealed that clusters II and IX contributed to the severity of lesion symptoms in N. benthamiana, as well as in Arabidopsis and tomato. The results support the hypothesis that the host ranges of P. syringae pathovars are limited by the complex interactions of effector repertoires with plant anti-effector surveillance systems, and they demonstrate that N. benthamiana can be a useful model host for DC3000.