Characterizing gene networks involved in cell envelope development in Rhizobium leguminosarum.

表征参与豆根瘤菌细胞包膜发育的基因网络。

• 批准号: RGPIN-2016-05670
• 负责人: Yost, Christopher
• 金额: $ 3.21万
• 依托单位: University of Regina
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=745957
• 关键词: Characterizing; gene; networks; involved; cell

Legume plants include several important food crops such as soybean and lentils, and have the ability to exist in symbiosis with nitrogen fixing bacteria (collectively termed rhizobia), whereby the bacteria live in root nodules and reduce atmospheric nitrogen to ammonia. The fixed nitrogen is assimilated by the plant to meet its nitrogen requirements. Fundamental discovery-based research is necessary to unravel the genetic traits and biological mechanisms that are important for rhizobia to successfully colonize the legume rhizosphere and adapt to stresses encountered during rhizosphere colonization and plant nodulation. The bacterial cell envelope is a well-known cellular feature that is important to the survival of bacteria in the environment and during colonization of host organisms. It is the first point of contact between a cell and its environment, and also functions to maintain cell integrity and protects the cell from toxic substances. The genetic networks involved in cell envelope adaptation are only partially described in rhizobia, despite the envelope's importance in rhizosphere survival and plant nodulation. My lab studies Rhizobium leguminosarum (a symbiont of peas and lentils) as a model species to characterize genetic networks involved in cell envelope development in Gram negative bacteria. In this renewal application the student trainees will focus on identifying new envelope regulatory networks, and determine how these networks are integrated with known regulatory systems such as the cell cycle regulator, CbrA. The research plan will leverage our capacity in next generation sequencing applications, such as RNA-Seq to characterize conserved DNA motifs that are important cis elements for regulation of envelope genes, and interrogate transcriptional changes caused by mutations to key cell envelope genes. We have recently developed a genetic tool for high throughput transposon mutagenesis screening (INSeq) in rhizobia. We will use this tool as a complement to the RNA-Seq experiments to identify novel genes important in cell envelope function and adaptation, particularly in response to plant derived antimicrobial peptides. The high throughput screening nature of the INSeq approach (millions of transposon mutants can be screened), and our recently completed reference library of core essential genes, developed from previous INSeq experiments, will greatly facilitate our goal of identifying new genes involved in cell envelope adaptation during rhizosphere and plant colonization. Combined with the RNA-Seq experiments we will be able to generate a more refined model of cell envelope regulatory networks in an agriculturally important bacterial species.

豆科植物包括几种重要的食物作物，例如大豆和小扁豆，并且具有与氮固定细菌（统称为根瘤菌）中的共生能力，从而使细菌生活在根结节中并将大气氮降低到ammonia。固定的氮被植物同化以满足其氮需求。基于发现的基本研究对于揭示对根瘤菌成功定居豆类根际并适应根际结合期间遇到的压力和植物结节时遇到的压力至关重要的遗传特征和生物学机制是必不可少的。细菌细胞膜是一种众所周知的细胞特征，对在环境中和宿主生物的定殖过程中的生存至关重要。这是细胞及其环境之间的接触点，并且还起到维持细胞完整性并保护细胞免受有毒物质的功能。尽管包膜在根际存活和植物淋巴结中的重要性，但在根瘤菌中涉及的遗传网络仅在根瘤菌中得到部分描述。我的实验室将根茎豆科植物（豌豆和小扁豆的共生体）研究为模型物种，以表征参与革兰氏阴性细菌细胞膜发育的遗传网络。在此续签应用中，学生学员将专注于确定新的包络调节网络，并确定如何将这些网络与已知调节系统（例如细胞周期调节器CBRA）集成。该研究计划将利用我们在下一代测序应用中的能力，例如RNA-seq来表征保守的DNA基序，这些基序是调节包膜基因的重要顺式元素，并询问由对关键细胞包膜基因突变引起的转录变化。 我们最近开发了一种用于根瘤菌中高通量转座子诱变筛查（INSEQ）的遗传工具。我们将使用此工具作为对RNA-Seq实验的补充，以识别在细胞包膜功能和适应中重要的新基因，特别是在响应植物衍生的抗菌肽时。 INSEQ方法的高吞吐量筛选性质（可以筛选数百万个转座子突变体），而我们最近完成的核心基本基因参考文献库，从以前的InSeq实验中开发出来，将极大地促进我们确定在刺激性和植物植物上适应细胞包络的新基因的目标。结合RNA-seq实验，我们将能够在农业重要的细菌物种中生成更精致的细胞包膜调节网络模型。