RpoN mediates biofilm formation by directly controlling vps gene cluster and c-di-GMP synthetic metabolism in V. alginolyticus

作者：Na Zhang, Yanhua Zeng, Jun Ye, Chuancao Lin, Xiaoxiao Gong, Hao Long, Haimin Chen, Zhenyu Xie · 发表于：Biofilm · 年份：2024 · DOI：10.1016/j.bioflm.2024.100242 · 被引用次数：5 · 研究领域：Bacterial biofilms and quorum sensing、Marine Toxins and Detection Methods、Oral microbiology and periodontitis research

Vibrio alginolyticus is a prevalent pathogen in both humans and marine species, exhibiting high adaptability to various adverse environmental conditions. Our previous studies have shown that Δ rpoN formed three enhanced biofilm types, including spectacular surface-attached biofilm (SB), scattered pellicle biofilm (PB), and colony rugosity. However, the precise mechanism through which rpoN regulates biofilm formation has remained unclear. Based on the critical role of Vibrio exopolysaccharide (VPS) in biofilm formation, several genes related to the production and regulation of VPS were characterized in V. alginolyticus . Our findings from mutant strains indicated that VPS has complete control over the formation of rugose colony morphology and PB, while it only partially contributes to SB formation. Among the four transcriptional regulators of the vps gene cluster, vpsR and VA3545 act as promoters, whereas VA3546 and VA2703 function as repressors. Through transcriptome analysis and c-di-GMP concentration determination, VA0356 and VA3580 which encoded diguanylate cyclase were found to mediate the Δ rpoN biofilm formation. As a central regulator, rpoN governed biofilm formation through two regulatory pathways. Firstly, it directly bound to the upstream region of VA4206 to regulate the expression of the vps gene cluster (VA4206-VA4196). Secondly, it directly and indirectly modulated c-di-GMP synthesis gene VA3580 and VA0356, respectively, thereby affecting c-di-GMP concentration a...