Sharma Anuj, Iruegas-Bocardo Fernanda, Bibi Shaheen, Chen Yun-Chu, Kim Jung-Gun, Abrahamian Peter, Minsavage Gerald V, Hurlbert Jason C, Vallad Gary E, Mudgett Mary B, Jones Jeffrey B, Goss Erica M
Plant Pathology Department, University of Florida, Gainesville, FL 32611, U.S.A.
Gulf Coast Research and Education Center, University of Florida, Gainesville, FL 32611, U.S.A.
Mol Plant Microbe Interact. 2024 Oct;37(10):736-747. doi: 10.1094/MPMI-05-24-0048-R. Epub 2024 Oct 28.
Type III effectors (T3Es) are major determinants of virulence and targets for resistance breeding. XopJ2 (synonym AvrBsT) is a highly conserved YopJ-family T3E acquired by , the pathogen responsible for bacterial spot disease of tomato. In this study, we characterized a new variant (XopJ2b) of XopJ2, which is predicted to have a similar three-dimensional (3D) structure as the canonical XopJ2 (XopJ2a) despite sharing only 70% sequence identity. XopJ2b carries an acetyltransferase domain and the critical residues required for its activity, and the positions of these residues are predicted to be conserved in the 3D structure of the proteins. We demonstrated that XopJ2b is a functional T3E and triggers a hypersensitive response (HR) when translocated into pepper cells. Like XopJ2a, XopJ2b triggers HR in that is suppressed by the deacetylase, SOBER1. We found in genome sequences of , , , and strains, suggesting widespread horizontal transfer. In , was present in strains collected in North America, Africa, Asia, Australia, and Europe, whereas had a narrower geographic distribution. This study expands the T3E repertoire, demonstrates functional conservation in T3E evolution, and further supports the importance of XopJ2 in fitness on tomato. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
III型效应蛋白（T3Es）是毒力的主要决定因素和抗病育种的靶点。XopJ2（同义词AvrBsT）是一种高度保守的YopJ家族T3E，由引起番茄细菌性斑点病的病原体获得。在本研究中，我们鉴定了XopJ2的一个新变体（XopJ2b），尽管其序列同一性仅为70%，但预测其具有与典型XopJ2（XopJ2a）相似的三维（3D）结构。XopJ2b携带一个乙酰转移酶结构域及其活性所需的关键残基，并且这些残基的位置预计在蛋白质的3D结构中是保守的。我们证明XopJ2b是一种功能性T3E，当转运到辣椒细胞中时会引发超敏反应（HR）。与XopJ2a一样，XopJ2b在被脱乙酰酶SOBER1抑制的情况下在 中引发HR。我们在 、 、 和 菌株的基因组序列中发现了 ，这表明广泛的水平转移。在 中， 在北美、非洲、亚洲、澳大利亚和欧洲收集的菌株中存在，而 的地理分布较窄。本研究扩展了 的T3E库，证明了T3E进化中的功能保守性，并进一步支持了XopJ2在 对番茄适应性中的重要性。[公式：见正文] 版权所有©2024作者。这是一篇根据CC BY-NC-ND 4.0国际许可分发的开放获取文章。
