| 摘要: |
| 【目的】通过同源重组技术敲除嗜线虫致病杆菌（Xenorhabdus nematophila） YL001中cpxR基因，为进一步研究CpxR调节子调控抗菌物质产生的机理奠定基础。【方法】通过融合PCR技术，将cpxR基因的上、下游同源片段及质粒pJCV53上的卡那抗性基因Kmr 3个片段连接，克隆到自杀载体pDM4中，将重组质粒转化到大肠杆菌S17-1λpir中，经接合转移导入嗜线虫致病杆菌内，通过同源重组敲除cpxR基因；采用琼脂扩散法和抑制菌丝生长速率法分别测定突变菌株对枯草芽孢杆菌和番茄灰霉病菌的抑制作用。【结果】从X.nematophila YL001基因组中成功敲除cpxR基因，得到了ΔcpxR突变菌株；ΔcpxR突变菌株对枯草芽孢杆菌和番茄灰霉病菌的抑制作用较野生菌株分别提高了1.4和1.7倍。【结论】CpxR负向调控嗜线虫致病杆菌YL001抗菌物质的产生。 |
| 关键词: 嗜线虫致病杆菌YL001 cpxR基因 基因敲除 抗菌活性 |
| DOI： |
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| 基金项目:国家自然科学基金项目（31171910）；陕西省自然科学基金重点项目（2014JZ004）；中央高校基本科研项目（ZD2013003） |
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| Construction of cpxR gene deletion mutant strain of Xenorhabdus nematophila YL001 and study of its antimicrobial activity |
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TANG Qian,ZHANG Shujing,GUO Qiangwei,et al
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| Abstract: |
| 【Objective】The cpxR gene of nematode pathogenic bacteriaXenorhabdus nematophila YL001 was knocked out by allelic exchange to provide basis for researching regulatory mechanism of CpxR on production of antimicrobial substances.【Method】In this study,the upstream and downstream flanking DNA fragments of target gene and the kanamycin resistant gene Kmr were fused by PCR before being cloned into the suicide vector pDM4.The recombinant plasmid was introduced into Escherichila coli strain S17-1λpir and transferred into X.nematophila by conjugation.Then,the inhibitory effect of the mutant strain against Bacillus subtilis and Botrytis cinerea was determined.【Result】The ΔcpxR mutant strain was obtained successfully,and the antimicrobial activities of mutant strains against B.subtilis and B.cinerea were increased by 1.4 and 1.7 times compared with those of the wild strain.【Conclusion】CpxR negatively regulates the production of antimicrobial substances of X.nematophila YL001. |
| Key words: Xenorhabdus nematophila YL001 cpxR gene knockout antimicrobial activity |
