Data_Sheet_1_Understanding the mechanisms of halotolerance in members of Pontixanthobacter and Allopontixanthobacter by comparative genome analysis.csv

Halotolerant microorganisms have developed versatile mechanisms for coping with saline stress. With the increasing number of isolated halotolerant strains and their genomes being sequenced, comparative genome analysis would help understand the mechanisms of salt tolerance. Six type strains of Pontixanthobacter and Allopontixanthobacter, two phylogenetically close genera, were isolated from diverse salty environments and showed different NaCl tolerances, from 3 to 10% (w/v). Based on the co-occurrence greater than 0.8 between halotolerance and open reading frame (ORF) among the six strains, possible explanations for halotolerance were discussed regarding osmolyte, membrane permeability, transportation, intracellular signaling, polysaccharide biosynthesis, and SOS response, which provided hypotheses for further investigations. The strategy of analyzing genome-wide co-occurrence between genetic diversity and physiological characteristics sheds light on how microorganisms adapt to the environment.

耐盐微生物（halotolerant microorganisms）已演化出多样的盐胁迫应对机制。随着分离获得的耐盐菌株数量不断增加，且其基因组测序工作陆续完成，比较基因组分析将有助于阐明微生物的耐盐机制。本研究从多种盐渍生境中分离得到系统发育关系相近的两个属——Pontixanthobacter属和Allopontixanthobacter属的6株模式菌株（type strains），这些菌株对NaCl的耐受范围为3%至10%（w/v）。基于这6株菌株中耐盐性与开放阅读框（open reading frame, ORF）之间共现系数大于0.8的关联，本研究围绕渗透调节物质（osmolyte）、细胞膜通透性、物质转运、细胞内信号传导、多糖生物合成以及SOS响应（SOS response）等多个维度探讨了耐盐性的潜在机制，为后续相关研究提供了可供检验的假说。这种分析遗传多样性与生理特征之间全基因组共现关联的研究策略，为解析微生物的环境适应机制提供了新的视角。