嗜麦芽糖寡氧单胞菌H002的基因组分析及对铀胁迫的转录组响应

Genomic analysis and transcriptomic response to uranium stress of Stenotrophomonas maltophilia H002

为探究嗜麦芽糖寡氧单胞菌H002响应金属铀冲击的分子机制及生物修复铀污染的潜力,本研究从基因组和转录组两个层面进行了分析.基因组测序结果表明,H002基因组大小为5 099 056 bp,预测编码4780个蛋白;与其他6个近缘菌株相比,H002拥有344个独特的编码基因,涉及膜转运、细胞运动和分泌等功能.转录组分析显示,在铀胁迫的早期(1 h),差异基因主要富集于细胞运动、分泌、蛋白质和肽聚糖合成等KEGG途径.部分分泌通道相关基因的表达下调,可降低细胞对铀离子的摄取,进而减轻铀离子对细胞的毒性.在铀胁迫的后期(2 h和4 h),参与铀生物矿化的磷酸酶相关基因和能够提供还原电子的细胞色素c基因的表达上调,能以主动方式降低铀的细胞毒性.

To explore the molecular mechanism of Stenotrophomonas maltophilia Ho02 in response to metal uranium impact and the potential of bioremediation of uranium pollution,genome and transcriptome analyses were performed in this study.It was shown that the H002 genome consists of 5099056 bp to encode 4780 proteins.Compared with the 6 homologous strains,Ho02 encodes 344 unique proteins,mainly involved in membrane transport,cell motility and secretion.Transcriptome analysis revealed that in the early stage(1 h)of uranium stress,the differentially expressed genes were mainly enriched in KEGG pathways such as cell mobility and secretion,the biosynthesis of protein and peptidoglycan.The downregulation of partial secretion channel-related genes may reduce the absorption of uranium ions,hence decreasing cellular toxicity.In the later stage(2 h and 4 h)of uranium stress,upregulation of the genes encoding phosphatases involved in uranium mineralization and the cytochrome c proteins,which can provide the reducing electronics,may help reduce the toxicity to the cells.