A Pseudomonas syringae pv. tomato avrE1/hopM1 mutant is severely reduced in growth and lesion formation in tomato
A Pseudomonas syringae pv. tomato avrE1/hopM1 mutant is severely reduced in growth and lesion formation in tomato
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DOI：
10.1094/mpmi-19-0099
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发表时间：
2006-02-01
影响因子：
3.5
通讯作者：
Collmer, A
中科院分区：
文献类型：
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作者：
Badel, JL;Shimizu, R;Collmer, A
模式植物病原菌假单胞菌（Pseudomonaserichingae pv.）番茄DC 3000生长并在其宿主番茄的叶片中产生坏死病变。这两种能力都依赖于过敏反应和致病性（Hrp）III型分泌系统（TTSS），该系统将多种效应蛋白易位到植物细胞中。一个先前构建的DC 3000突变体与9.3 kb的缺失HRP致病岛保守效应基因座（CEL）的番茄叶片的生长和病变形成强烈减少。Delta CEL突变影响三个推定或已知的效应基因：avrE 1、hopM 1和hopAA 1 -1。DC 3000、烟草赤星病菌的基因组序列比较phaseolicola 1448 A，以及大豆疫霉致病变种Escherichiapv. B728 a揭示了这些是所有三种菌株的CEL中存在的唯一效应基因。基于AvrE I的前315个氨基酸与Cya易位报告基因融合的表现，AvrE 1显示携带功能性TTSS易位信号。DC 3000 Δ avrE 1突变体在其产生病变的能力，但不是在其在宿主番茄叶片中生长的能力降低。在农杆菌介导的瞬时表达实验中，从35 S启动子表达的AvrE 1引起非宿主烟草叶和宿主番茄叶中的细胞死亡。涉及avrE 1、hopM 1和hopAA 1 -1的组合的突变揭示了avrE 1和hopM 1两者的缺失再现了Delta CEL突变体的强烈降低的生长和病变表型。此外，涉及不同水平的接种物和电解质渗漏的定量测定显示，aw-E1/hopM 1和Delta CEL突变体在非宿主N中引起过敏反应的能力都部分受损。本萨米亚那树叶。然而，avrE 1/hopM 1突变体将AvrPto 1（（1-100））-Cya传递到非宿主N的能力没有受损。benthamiana或宿主番茄叶在接种后的前9小时期间。这些数据表明，AvrE 1在植物细胞内起作用并促进病变形成，AvrE 1和HopM 1的联合作用在促进植物中细菌生长方面特别重要。
The model plant pathogen Pseudomonas syringae pv. tomato DC3000 grows and produces necrotic lesions in the leaves of its host, tomato. Both abilities are dependent upon the hypersensitive response and pathogenicity (Hrp) type III secretion system (TTSS), which translocates multiple effector proteins into plant cells. A previously constructed DC3000 mutant with a 9.3-kb deletion in the Hrp pathogenicity island conserved effector locus (CEL) was strongly reduced in growth and lesion formation in tomato leaves. The Delta CEL mutation affects three putative or known effector genes: avrE1, hopM1, and hopAA1-1. Comparison of genomic sequences of DC3000, P syringae pv. phaseolicola 1448A, and E syringae pv. syringae B728a revealed that these are the only effector genes present in the CEL of all three strains. AvrE1 was shown to carry functional TTSS translocation signals based on the performance of a fusion of the first 315 amino acids of AvrE I to the Cya translocation reporter. A DC3000 Delta avrE1 mutant was reduced in its ability to produce lesions but not in its ability to grow in host tomato leaves. AvrE1 expressed from the 35S promoter elicited cell death in nonhost Nicotiana tabacum leaves and host tomato leaves in Agrobacteritum-mediated transient expression experiments. Mutations involving combinations of avrE1, hopM1, and hopAA1-1 revealed that deletion of both avrE1 and hopM1 reproduced the strongly reduced growth and lesion phenotype of the Delta CEL mutant. Furthermore, quantitative assays involving different levels of inoculum and electrolyte leakage revealed that the aw-E1/hopM1 and Delta CEL mutants both were partially impaired in their ability to elicit the hypersensitive response in nonhost N. benthamiana leaves. However, the avrE1/hopM1 mutant was not impaired in its ability to deliver AvrPto1((1-100))-Cya to nonhost N. benthamiana or host tomato leaves during the first 9 h after inoculation. These data suggest that AvrE1 acts within plant cells and promotes lesion formation and that the combined action of AvrE1 and HopM1 is particularly important in promoting bacterial growth in planta.