Identification of genes involved in regulating MnSOD production and root colonization in Bacillus cereus 905
Identification of genes involved in regulating MnSOD production and root colonization in Bacillus cereus 905
复制标题
蜡样芽孢杆菌 905 中参与调节 MnSOD 产生和根定植的基因的鉴定
DOI：
--
复制
发表时间：
--
影响因子：
4.8
通讯作者：
WANG Qi
中科院分区：
文献类型：
--
作者：
GAO Tan-tan;DING Ming-zheng;LI Yan;ZENG Qing-chao;WANG Qi
蜡样芽孢杆菌 905 中编码 sodA2 的含锰超氧化物歧化酶 (MnSOD2) 在抗氧化应激、营养利用、根际和叶际定殖中发挥着重要作用。然而，蜡样芽胞杆菌中参与调节 sodA2 表达的基因尚未明确阐明。在本研究中，利用转座子 TnYLB-1 构建了全基因组随机插入诱变，以鉴定调节 sodA2 表达的新基因。最终获得了7个在mRNA和蛋白质水平上改变sodA2表达的突变体。序列分析和 BLAST 数据表明，蜡样芽胞杆菌 905 中被 TnYLB-1 破坏的基因与蜡样芽孢杆菌型菌株 ATCC 14579 中的基因具有高度保守性。这些基因编码热诱导转录抑制子、氯离子通道蛋白、重组酶 A、亚铁转运蛋白、核苷二磷酸激酶和组氨酸解氨酶。此外，我们还提供了证据表明，调节sodA2表达的基因可以影响B. cereus 905在小麦根部的定植能力，下调sodA2基因表达的基因显着减少了细菌在小麦根部的定植，而MnSOD2活性增加的突变体可以在一定程度上提高小麦根部的细菌种群密度。我们的工作提供了多个基因参与 MnSOD2 产生和小麦根部定植的信息，以及这些基因如何调节 sodA2 表达和根部定植的分子调控途径需要进一步广泛研究。
The sodA2-encoding manganese-containing superoxide dismutase (MnSOD2) in Bacillus cereus 905 plays an essential role in antioxidative stress, nutrition utilization, rhizosphere and phyllosphere colonization. However, the genes involved in regulating the sodA2 expression have not been clearly elucidated in B. cereus. In this study, a genome-wide random insertion mutagenesis was constructed by using a transposon TnYLB-1 to identify novel genes regulating the sodA2 expression. Seven mutants that changed the sodA2 expression at both mRNA and protein levels were finally obtained. Sequence analysis and BLAST data showed that the genes disrupted by the TnYLB-1 in the B. cereus 905 share high conservations with those in the B. cereus type strain, ATCC 14579. These genes encode heat-inducible transcription repressor, chloride channel protein, recombinase A, ferrous iron transport protein, nucleoside diphosphate kinase, and histidine ammonia-lyase. Besides, we also provided the evidence that the genes regulating the sodA2 expression could influence colonization ability of B. cereus 905 on the wheat roots, those genes downregulating expression of the sodA2 gene significantly reduced the bacterial colonization on the wheat roots and the mutants with increased MnSOD2 activities could enhance the bacterial population densities on the wheat roots to a certain degree. Our work provide information that multiple genes are involved in MnSOD2 production and wheat roots colonization and the molecular regulatory pathways that how these genes modulate the sodA2 expression and root colonization need to be investigated extensively in the further.