Ziye Shang, Yuqiang Zhao, Shitong Wu, Ling Cai, Chenchao Sun, Jun Wang, Weirong Gong, Yanli Tian, Baishi Hu
College of Plant Protection and Key Laboratory of Integrated Management of Crop Diseases and Pests, Nanjing Agricultural University, Nanjing, China.
Key Laboratory of Plant Quarantine Pests Monitoring and Control, Ministry of Agriculture and Rural Affairs, Nanjing, China.
Front Microbiol. 2024 Jul 23;15:1431029. doi: 10.3389/fmicb.2024.1431029. eCollection 2024.
ClpA is a widely conserved protease in bacteria that plays a key role in virulence. To investigate its specific mechanism of action in the pathogenicity of (formerly , we constructed a deletion mutant, Δ. The Δ mutant of displayed reduced virulence on melon seedlings, and reduced motility, swarming ability, and antioxidant capacity. On the other hand, the deletion of mutant reduced the resistance to elevated temperature and enhanced biofilm formation ability. Using qRT-PCR, we observed that negatively regulates the expression of the virulence-related genes , , , and , while positively regulating , , and . Bacterial double hybrid and Glutathione-S-transferase pulldown (GST-pulldown) results showed that ClpA interacts directly with RepA, and negatively regulates the expression of . After deletion of the gene, the pathogenicity of was lost, biofilm formation ability was enhanced, and the expression of , , and was positively regulated. These results indicate that ClpA plays a key role in the regulation of several virulence traits of , paving the way for future studies to better elucidate the virulence mechanisms of this bacterial plant pathogen.
ClpA是细菌中一种广泛保守的蛋白酶，在毒力方面发挥关键作用。为了研究其在（以前为，）致病性中的具体作用机制，我们构建了一个缺失突变体Δ。的Δ突变体在甜瓜幼苗上显示出降低的毒力，以及降低的运动性、群体运动能力和抗氧化能力。另一方面，缺失突变体降低了对高温的抗性并增强了生物膜形成能力。使用qRT-PCR，我们观察到负向调节毒力相关基因、、、和的表达，同时正向调节、和。细菌双杂交和谷胱甘肽-S-转移酶下拉（GST下拉）结果表明，ClpA直接与RepA相互作用，并负向调节的表达。基因缺失后，的致病性丧失，生物膜形成能力增强，并且、和的表达被正向调节。这些结果表明，ClpA在调节的几种毒力特性中起关键作用，为未来更好地阐明这种细菌性植物病原体的毒力机制的研究铺平了道路。
