细菌的σ54(R poN)是一类可选择性识别启动子序列的σ因子,主要参与环境适应、细胞生理过程等,如氮代谢、鞭毛和菌毛的生物合成。在一些病原菌中,σ54也与致病性密切有关。为了明确σ54在野油菜黄单胞菌野油菜致病变种(X cc)中是否参与...细菌的σ54(R poN)是一类可选择性识别启动子序列的σ因子,主要参与环境适应、细胞生理过程等,如氮代谢、鞭毛和菌毛的生物合成。在一些病原菌中,σ54也与致病性密切有关。为了明确σ54在野油菜黄单胞菌野油菜致病变种(X cc)中是否参与致病过程,用同源单交换定点突变方法,将X cc 8004中的两个σ54编码基因rp oN 1(XC 1256)和rp oN 2(XC 2168)做单突变及双突变。突变体表型分析结果表明,单个和同时突变rp oN 1和rp oN 2基因均不影响野油菜黄单胞菌的正常生长,对胞外多糖(EPS)产生、胞外酶的合成也无明显影响。植株致病性检测结果表明,rp oN 1和rp oN 2基因的单突变或双突变体的致病力与野生型菌株没有显著差异,表明野油菜黄单胞菌野油菜致病变种的致病过程不需要σ54因子参与。展开更多
The sigma factor 54（σ^（54）） controls the expression of many genes in response to nutritional and environmental conditions. There are two σ^（54） genes, rpo N1（XAC1969） and rpo N2（XAC2972）, in Xanthomonas ci...The sigma factor 54（σ^（54）） controls the expression of many genes in response to nutritional and environmental conditions. There are two σ^（54） genes, rpo N1（XAC1969） and rpo N2（XAC2972）, in Xanthomonas citri subsp. citri. To investigate their functions, the deletion mutants ΔrpoN1, ΔrpoN2 and ΔrpoN1N2 were constructed in this study. All the mutants delayed canker development in low concentration inoculation in citrus plants. The bacterial growth of mutants was retarded in the medium supplemented with nitrogen and carbon resources. Under either condition, the influence degree caused by deletion of rpoN 2 was larger than the deletion of rpoN 1. Remarkably, the mutant ΔrpoN 1 showed a reduction in cell motility, while the mutant Δrpo N2 increased cell motility. Our data suggested that the rpoN 1 and rpoN 2 play diverse roles in X. citri subsp. citri.展开更多
文摘细菌的σ54(R poN)是一类可选择性识别启动子序列的σ因子,主要参与环境适应、细胞生理过程等,如氮代谢、鞭毛和菌毛的生物合成。在一些病原菌中,σ54也与致病性密切有关。为了明确σ54在野油菜黄单胞菌野油菜致病变种(X cc)中是否参与致病过程,用同源单交换定点突变方法,将X cc 8004中的两个σ54编码基因rp oN 1(XC 1256)和rp oN 2(XC 2168)做单突变及双突变。突变体表型分析结果表明,单个和同时突变rp oN 1和rp oN 2基因均不影响野油菜黄单胞菌的正常生长,对胞外多糖(EPS)产生、胞外酶的合成也无明显影响。植株致病性检测结果表明,rp oN 1和rp oN 2基因的单突变或双突变体的致病力与野生型菌株没有显著差异,表明野油菜黄单胞菌野油菜致病变种的致病过程不需要σ54因子参与。
基金supported by the National Natural Science Foundation of China(31171832)the Jiangsu Agriculture Science and Technology Innovation Fund,China(CX(11)4056)
文摘The sigma factor 54（σ^（54）） controls the expression of many genes in response to nutritional and environmental conditions. There are two σ^（54） genes, rpo N1（XAC1969） and rpo N2（XAC2972）, in Xanthomonas citri subsp. citri. To investigate their functions, the deletion mutants ΔrpoN1, ΔrpoN2 and ΔrpoN1N2 were constructed in this study. All the mutants delayed canker development in low concentration inoculation in citrus plants. The bacterial growth of mutants was retarded in the medium supplemented with nitrogen and carbon resources. Under either condition, the influence degree caused by deletion of rpoN 2 was larger than the deletion of rpoN 1. Remarkably, the mutant ΔrpoN 1 showed a reduction in cell motility, while the mutant Δrpo N2 increased cell motility. Our data suggested that the rpoN 1 and rpoN 2 play diverse roles in X. citri subsp. citri.
