Zhang Yi, Gao Yuhan, Liang Yingbo, Dong Yijie, Yang Xiufen, Yuan Jingjing, Qiu Dewen
Institute of Plant Protection (CAAS), Haidian, China.
Front Plant Sci. 2017 Oct 31;8:1880. doi: 10.3389/fpls.2017.01880. eCollection 2017.
During pathogenic infection, hundreds of proteins that play vital roles in the -host interaction are secreted. In this study, an integrated proteomic analysis of secreted . proteins was performed, and a conserved secretory protein, designated VdCP1, was identified as a member of the SnodProt1 phytotoxin family. An expression analysis of the gene revealed that the transcript is present in every condition studied and displays elevated expression throughout the infection process. To investigate the natural role of VdCP1 in , two knockout mutants and their complementation strains were generated. Bioassays of these mutants revealed no obvious phenotypic differences from the wild-type (WT) in terms of mycelial growth, conidial production or mycelial/spore morphology. However, compared with the WT, the knockout mutants displayed attenuated pathogenicity in cotton plants. Furthermore, treating plants with purified recombinant VdCP1 protein expressed in induced the accumulation of reactive oxygen species (ROS), expression of several defense-related genes, leakage of ion electrolytes, enhancement of defense-related enzyme activity and production of salicylic acid. Moreover, VdCP1 conferred resistance to and pv. tabaci in tobacco and to in cotton. Further research revealed that VdCP1 possesses chitin-binding properties and that the growth of knockout mutants was more affected by treatments with chitinase, indicating that VdCP1 could protect cell wall from enzymatic degradation, which suggests an effector role of VdCP1 in infecting hosts.
在致病性感染过程中，数百种在宿主相互作用中起关键作用的蛋白质被分泌出来。在本研究中，对分泌蛋白进行了综合蛋白质组学分析，并鉴定出一种保守的分泌蛋白，命名为VdCP1，它是SnodProt1植物毒素家族的成员。对该基因的表达分析表明，转录本在所有研究条件下均存在，并且在整个感染过程中表达升高。为了研究VdCP1在……中的天然作用，构建了两个基因敲除突变体及其互补菌株。对这些突变体的生物测定表明，在菌丝生长、分生孢子产生或菌丝/孢子形态方面，与野生型（WT）没有明显的表型差异。然而，与WT相比，基因敲除突变体在棉花植株中的致病性减弱。此外，用在……中表达的纯化重组VdCP1蛋白处理植物，可诱导活性氧（ROS）的积累、几个防御相关基因的表达、离子电解质的渗漏、防御相关酶活性的增强以及水杨酸的产生。此外，VdCP1赋予烟草对……和烟草野火病菌pv. tabaci以及棉花对……的抗性。进一步的研究表明，VdCP1具有几丁质结合特性，基因敲除突变体的生长受几丁质酶处理的影响更大，这表明VdCP1可以保护……细胞壁免受酶解降解，这表明VdCP1在感染宿主中起效应子作用。
