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| 水稻细菌性条斑病菌中一个调控致病性的DNA结合蛋白负调控胞外酶活性 | |
| 引用本文： | 李瑞芳,覃祚树,王欣欣,陈小林,岑贞陆,颜群,晏卫红,韦善富,陆光涛.水稻细菌性条斑病菌中一个调控致病性的DNA结合蛋白负调控胞外酶活性[J].植物病理学报,2021,51(4):572-582. |
| 作者姓名： | 李瑞芳 覃祚树 王欣欣 陈小林 岑贞陆 颜群 晏卫红 韦善富 陆光涛 |
| 作者单位： | 广西农业科学院植物保护研究所, 南宁 530007; 广西作物病虫害生物学重点实验室, 南宁 530007; 广西大学亚热带农业生物资源保护与利用国家重点实验室/生命科学与技术学院, 南宁 530007 |
| 基金项目： | 国家自然科学基金(31660506);广西自然科学基金(2015GXNSFBA139110);广西作物病虫害生物学重点实验室系统课题(2019-ST-07);国家重点研发计划课题(2018YFD0200306);广西农业科学院团队项目(2015YT36) |
| 摘 要： | 原核革兰氏阴性菌稻黄单胞菌稻生致病变种 (又称水稻细菌性条斑病菌,Xanthomonas oryzae pv. oryzicola, Xoc)是引起水稻细菌性条斑病的病原物,该病是水稻粮食生产中的严重病害之一。我们的前期工作对广西农科院分离到的Xoc菌株GX01进行基因组序列分析,发现一个编号为gx01_0566的基因可能编码一个Fis家族的DNA结合蛋白。本工作采用自杀质粒pK18mobsacB介导的方法来构建该基因的缺失突变体,并对突变体进行反式互补。表型分析发现,gx01_0566基因的突变体在寄主水稻日本晴上的致病力显著下降,但其胞外多糖产量与野生型基本一致,胞外酶尤其是胞外纤维素酶活性却大幅度提高。为进一步研究gx01_0566基因在Xoc中调控胞外纤维素酶的机理,我们对该基因的产物进行过量表达和纯化,并通过凝胶阻滞实验和实时定量PCR实验分析,发现gx01_0566编码产物能够结合在一些编码纤维素酶的基因的启动子上,负调控这些纤维素酶基因的表达。 |
| 关 键 词： | 水稻细菌性条斑病菌 DNA结合蛋白 胞外酶纤维素酶 致病性 |
| 收稿时间： | 2020-07-15 |
A DNA-binding protein required for virulence negatively regulates the activity of extracellular enzymes in Xanthomonas oryzae pv. oryzicola |
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| LI Rui-fang,QIN Zuo-shu,WANG Xin-xin,CHEN Xiao-lin,CEN Zen-lu,YAN Qun,YAN Wei-hong,WEI Shan-fu,LU Guang-tao.A DNA-binding protein required for virulence negatively regulates the activity of extracellular enzymes in Xanthomonas oryzae pv. oryzicola[J].Acta Phytopathologica Sinica,2021,51(4):572-582. | |
| Authors: | LI Rui-fang QIN Zuo-shu WANG Xin-xin CHEN Xiao-lin CEN Zen-lu YAN Qun YAN Wei-hong WEI Shan-fu LU Guang-tao |
| Institution: | Plant Protection Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007,China; Guangxi Key Laboratory of Biology for Crop Diseases and Insect Pests, Nanning 530007, China; State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning 530007, China |
| Abstract: | The prokaryotic Gram-negative bacterium Xanthomonas oryzae pv. oryzicola (Xoc) is the causal agent of bacterial leaf streak disease of rice. In our previous work, a scanning of the genome sequence of the Xoc wild type strain GX01 isolated from Guangxi, China, revealed that a gene named gx01_0566 might encode a DNA-binding protein belonging to the Fis family. To facilitate the characterization of gx01_0566, a deletion mutant was constructed by using the suicide vector pK18mobsacB and complemented in trans. Phenotypic analysis revealed that the virulence of the gx01_0566 mutant in the host plant Japonica cultivar Nipponbare was greatly reduced compared with wild-type, while the exopolysaccharide production of the gx01_0566 mutant is comparable to that of the wild-type. Interestingly, activities of the exoenzymes such as the endoglucanase increased greatly in the gx01_0566 mutant strain compared with the wild-type. To further investigate the role of the gx01_0566 gene in regulation of the endoglucanase activity, gx01_0566 protein was overproduced and purified. Electrophoresis mobility shift assays indicated that gx01_0566 protein binds to the promoter of certain endoglucanases-encoding genes such as gx01_0026 and gx01_4282. Furthermore, quantitative real-time PCR revealed that the expression level of several endoglucanase-encoding genes was enhanced greatly in the mutant compared with the wild-type, implying that the gx01_0566 protein represses the expression of these endoglucanases encoding genes via directly binding to their promoters. |
| Keywords: | Xanthomonas oryzae pv oryzae DNA-binding protein Endoglucanase pathogenicity |
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