野油菜黄单胞菌hpa2基因的突变和功能分析

Mutagenesis and functional characterization of hpa2 gene in Xanthomonas campestris pv.campestris

利用自杀质粒pK18mob诱变野油菜黄单胞菌Xcc8004的hpa2基因,获得整合突变体PK3001。致病性和过敏反应检测发现,hpa2突变体PK3001过敏反应完全丧失,但致病性无明显变化。利用gus报告基因和RT-PCR检测hpa2基因的表达调控,结果表明,hpa2基因在基本培养基上高表达,且受hrpG、hrpX正向调控。

Mutant PK3001 was generated by the hpa2 gene of Xanthomonas campestris pv. campestris （Xcc） mutated with suicide plasmid pK18mob. The pathogenicity and hypersensitive reaction （HR） of mutant PK3001 were determined. The hpa2 mutant PK3001 didn＇t affect the virulence significantly but lost HR completely. The expression and regulation of the hpa2 gene were analyzed through gus report gene and RT-PCR. The results showed that the hpa2 gene was highly expressed in MMX and positively regulated by hrpG and hrpX.