Tan Xiaojuan, Yang Ting, Wu Minglong, Luo Liping, Zheng Ruyi, Liu Qianqian, Zhu Guoping, Sun Yang
Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, College of Life Sciences, Anhui Normal University, Wuhu, Anhui, 241000, China.
Biofilm. 2025 Jun 13;10:100295. doi: 10.1016/j.bioflm.2025.100295. eCollection 2025 Dec.
mailto:Soft rot caused by is an important bacterial disease affecting rice and other plants around the world. Several studies found that the specific virulence factor-modulating quorum sensing (-QS) system is present in bacteria. is the key member encoding a two-component system sensor histidine kinase. Therefore, to determine the effects of -QS on phenotypic features and virulence, the system was inactivated through the construction of a mutant in the WH1 strain. The results of the phenotypic features and pathogenicity assays revealed that the deletion of abolished motility and reduced biofilm-forming capacity. Moreover, the mutation had a limited role in regulating the activity of plant cell wall-degrading enzymes (PCWDEs) and decreased the maceration of potato tubers in the tested dicotyledonous plants. Importantly, the mutant became avirulent to the rice plants, although the gene mutation slightly increased rice seed germination. These features are considerably different from those that have been shown for other strains. Finally, our findings indicated that the system controls the motility of WH1 by regulating flagellar biosynthesis and biofilm formation, which is achieved by regulating the intracellular c-di-GMP level. Taken together, these findings highlight the complexity and plasticity of QS regulatory circuits in the strain.
由[具体细菌名称未给出]引起的软腐病是一种影响全球水稻和其他植物的重要细菌性病害。多项研究发现，细菌中存在特定的毒力因子调节群体感应（-QS）系统。[具体基因名称未给出]是编码双组分系统传感器组氨酸激酶的关键成员。因此，为了确定-QS对表型特征和毒力的影响，通过在WH1菌株中构建[具体基因名称未给出]突变体使该系统失活。表型特征和致病性测定结果表明，[具体基因名称未给出]的缺失消除了运动性并降低了生物膜形成能力。此外，该突变在调节植物细胞壁降解酶（PCWDEs）的活性方面作用有限，并降低了受试双子叶植物中马铃薯块茎的浸解程度。重要的是，[具体基因名称未给出]突变体对水稻植株变得无毒，尽管基因突变略微提高了水稻种子的发芽率。这些特征与已报道的其他[具体细菌名称未给出]菌株的特征有很大不同。最后，我们的研究结果表明，[具体基因名称未给出]系统通过调节鞭毛生物合成和生物膜形成来控制WH1的运动性，这是通过调节细胞内c-di-GMP水平实现的。综上所述，这些发现突出了[具体细菌名称未给出]菌株中QS调控回路的复杂性和可塑性。
