野油菜黄单胞菌XC3813-3815基因启动子的定位分析

野油菜黄单胞菌野油菜致病变种（简称Xcc）是十字花科作物黑腐病的病原菌,同时也是发酵工业生产黄原胶的菌种。在以前的工作中,证实了Xcc8004菌株基因组中一个包含XC3813-3815三个基因的新位点与致病性和胞外多糖（EPS,又称黄原胶）合成有关。本工作通过PCR合成包含相应ORF及其上游不同长度的DNA片段,并克隆于不带启动子的质粒载体pLAFR6后,将所获的重组质粒互补相应的突变体。通过这一功能互补的方法,确定了这三个基因在其ORF上游约50bp内分别拥有自身的启动子。

Functional complementation analysis of the mutants of XC3813-3815 in Xanthomonas campestris

Xanthomonas campestris pv.campestris(Xcc) is the causal agency of the black rot disease of cruciferous plants,and the microorganism used for xanthan gum production in ferment industry.In previous work a novel locus,XC3813-3815,had been identified to be required for full virulence and extracellular polysaccharide(EPS,also called xanthan gum) production.Here the promoter region of XC3813-3815 was investigated.DNA fragments spanning downstream and different length of upstream region of open reading frame(ORF) were amplified by PCR and cloned into the promoterless plasmid pLAFR6,respectively.The resulting recombinant plasmids were introduced into the corresponding mutants for the complementation of these three genes mutants.By this method of functional complementation,the promoter for each of the three genes was limited to 50 bp upstream region of the corresponding ORF.