许多革兰氏阴性植物病原细菌通过Ⅲ型分泌系统(T3SS),将效应物蛋白分泌并转运进入植物体内,从而引起植物发病或过敏反应。效应物是病原细菌和植物分子互作的关键物质。全基因组筛选鉴定Ⅲ型效应物蛋白并研究其功能,对于解明病原菌的致病机理、寄主范围和进化具有重要意义。利用avrBs1作为报告基因,将其过敏反应诱导结构域(AvrBs1 59-444)克隆到不含启动子的穿梭质粒pLAFR6上,构建一个用于Ⅲ型效应物转运体外鉴定的报告质粒pLJB,并以已经鉴定为效应物基因的XC_1553的启动子验证该报告质粒,证明pLJB工作正常。该报告质粒为进一步进行全基因组筛选鉴定野油菜黄单胞菌Ⅲ型效应物提供材料。
Many Gram-negative phytopathogenic bacteria use Type Ⅲ secretion system (T3SS) to inject diverse virulence effectors into host cells resulting in pathogenicity or hypersensitive response (HR). To comprehensively understand bacterial pathogenesis, host range, and pathogen evolution, it is prerequisite to identify the Type Ⅲ effector repertoires of diverse phytopathogenic bacteria. A reporter plasmid for identifying the translocation of type Ⅲ effectors in vitro was constructed using avrBsl as a reporter. The HR inducing domain of AvrBsl (AvrBs1 59-444) was cloned into the promoterless shuttle vector pLAFR6, generated the reporter plasmid pLJB. The reporter plasmid was confirmed to work well using the promoter of XC_1553 which had been identified to be type effector before. This reporter plasmid provides useful vessel to genome-wide screen type Ⅲ effectors of Xanthomonas campestris.