Wang Xiaoyu, Wu Hao, Wang Lvjing, Wang Yihan, Wang Xuejun, Wang Haixia, Lu Zhenmei
MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China; Cancer Center, Zhejiang University, Hangzhou, 310058, China.
MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China.
Environ Res. 2023 Feb 15;219:115014. doi: 10.1016/j.envres.2022.115014. Epub 2022 Dec 19.
Hyperosmotic stress is one of the most ubiquitous stress factors in microbial habitats and impairs the efficiency of bacteria performing vital biochemical tasks. Sphingomonas serves as a 'superstar' of plant defense and pollutant degradation, and is widely existed in the environment. However, it is still unclear that how Sphingomonas sp. survives under hyperosmotic stress conditions. In this study, multiomics profiling analysis was conducted with S. melonis TY under hyperosmotic conditions to investigate the intracellular hyperosmotic responses. The transcriptome and proteome revealed that sensing systems, including most membrane protein coding genes were upregulated, genes related to two-component systems were tiered adjusted to reset the whole system, other stress response regulators such as sigma-70 were also significantly tiered upregulated. In addition, transport systems together with compatible solute biosynthesis related genes were significantly upregulated to accumulate intracellular nutrients and compatible solutes. When treated with hyperosmotic stress, redox-stress response systems were triggered and mechanosensitive channels together with ion transporters were induced to maintain cellular ion homeostasis. In addition, cellular concentration of c-di-guanosine monophosphate synthetase (c-di-GMP) was reduced, followed by negative influences on genes involved in flagellar assembly and chemotaxis pathways, leading to severe damage to the athletic ability of S. melonis TY, and causing detachments of biofilms. Briefly, this research revealed a comprehensive response mechanism of S. melonis TY exposure to hyperosmotic stress, and emphasized that flagellar assembly and biofilm formation were vulnerable to hyperosmotic conditions. Importance. Sphingomonas, a genus with versatile functions survives extensively, lauded for its prominent role in plant protection and environmental remediation. Current evidence shows that hyperosmotic stress as a ubiquitous environmental factor, usually threatens the survival of microbes and thus impairs the efficiency of their environmental functions. Thus, it is essential to explore the cellular responses to hyperosmotic stress. Hence, this research will greatly enhance our understanding of the global transcriptional and translational regulation of S. melonis TY in response to hyperosmotic stress, leading to broader perspectives on the impacts of stressful environments.
高渗胁迫是微生物栖息地中最普遍存在的胁迫因素之一，会损害细菌执行重要生化任务的效率。鞘氨醇单胞菌是植物防御和污染物降解方面的“明星”，广泛存在于环境中。然而，目前仍不清楚鞘氨醇单胞菌如何在高渗胁迫条件下存活。在本研究中，对高渗条件下的甜瓜鞘氨醇单胞菌TY进行了多组学分析，以研究其细胞内的高渗应激反应。转录组和蛋白质组分析表明，包括大多数膜蛋白编码基因在内的感知系统上调，与双组分系统相关的基因进行分层调整以重置整个系统，其他应激反应调节因子如sigma-70也显著分层上调。此外，运输系统以及与相容性溶质生物合成相关的基因显著上调，以积累细胞内营养物质和相容性溶质。当受到高渗胁迫时，氧化还原应激反应系统被触发，机械敏感通道以及离子转运体被诱导以维持细胞离子稳态。此外，细胞内双鸟苷单磷酸合成酶（c-di-GMP）的浓度降低，随后对鞭毛组装和趋化途径相关基因产生负面影响，导致甜瓜鞘氨醇单胞菌TY的运动能力严重受损，并导致生物膜脱落。简而言之，本研究揭示了甜瓜鞘氨醇单胞菌TY暴露于高渗胁迫下的综合反应机制，并强调鞭毛组装和生物膜形成易受高渗条件影响。重要性。鞘氨醇单胞菌属功能多样，广泛存活，因其在植物保护和环境修复中的突出作用而受到赞誉。目前的证据表明，高渗胁迫作为一种普遍存在的环境因素，通常会威胁微生物的生存，从而损害其环境功能的效率。因此，探索细胞对高渗胁迫的反应至关重要。因此，本研究将极大地增进我们对甜瓜鞘氨醇单胞菌TY响应高渗胁迫的全局转录和翻译调控的理解，从而对压力环境的影响有更广泛的认识。
