中文摘要：

十字花科黑腐病菌（Xanthomonas campestris pv．campestris，Xcc）8004菌株基因组中XC_3023注释为HrpW蛋白基因。本研究利用生物信息学和分子生物学技术，对HrpW基因进行功能鉴定。生物信息学分析发现HrpW蛋白具有Harpin特征：含有果胶裂解酶结构域，为酸性蛋白，富含甘氨酸和丝氨酸。转录分析结果发现hrpW基因自身有一较弱的启动子，受MMX基本培养基诱导表达。共转录分析结果表明hrpW基因与上游hrp E、hpa B基因共同转录。Westem blotting和转运分析结果显示，HrpW蛋白受Ⅲ型分泌系统（type Ⅲ secretion system，T3SS）依赖分泌，但不转运。植株试验结果发现纯化的HrpW蛋白能在烟草上诱发过敏反应（hypersensitive reaction，HR）。这些结果揭示XC_3023编码蛋白HrpW为Ⅲ型分泌系统分泌的Harpin蛋白。

英文摘要：

XC_3023 ofXanthomonas campestris pv. campestris （Xcc） 8004 is annotated to encode HrpW protein. The bioinformatics and molecular biology methods were employed to identify the function of hrp W in this research. Bioinformatics analysis showed that HrpW harbors the characteristics of Harpin： containing pectate lyase domain, acidic protein, and rich of glycine and serine. The results of transcriptional expression analysis indicated that hrpW has a weak promoter and its expression is induced in minimal medium MMX. Co-expression assay revealed that hrpW is co-expressed with upstream hrpE and hpaB. The results of Western blotting and translocation detection demonstrated that HrpW is secreted but not translocated via type m secretion system （T3SS）. Plant assay showed that the purified HrpW protein can elicit hypersensitive reaction （HR） in Nicotiana tabacum. All these results represented that HrpW is a T3SS-dependent Harpin protein.