Genetic control of alfalfa infection by the nitrogen fixing symbiotic bacterium Sinorhizobium meliloti

固氮共生菌苜蓿中华根瘤菌对苜蓿感染的遗传控制

• 批准号: 155385-2013
• 负责人: Charles, Trevor
• 金额: $ 3.64万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=629654
• 关键词: Genetic; control; alfalfa; infection; nitrogen

Nitrogen fixing nodules form on alfalfa roots as a result of infection by Sinorhizobium meliloti bacteria. This plant-microbe interaction is a complex developmental process that is a model system for study of symbiotic nitrogen fixation. Our research program uses bacterial genetic tools to study the control of infection by the ExoS-ChvI transcriptional regulatory system that coordinates the expression of a large number of genes both directly and indirectly. We are carrying out a detailed characterization of this regulatory system in an effort to determine its role in controlling infection. DNA binding screens are used to determine exactly which genes are directly turned off and on by this system, and we will improve the screen by incorporating Illumina DNA sequencing technology. We will try to determine the inducing signal, and we will also compare the pleiotropic phenotype of mutants of the regulatory system with the phenotypes of mutants of the individual target genes. Our work has the potential to greatly improve our understanding of the infection process, and this will impact not only on agricultural symbiotic nitrogen fixation improvements, but will also contribute to our overall research program by further developing the fundamentals of bacterial molecular genetics. The work will be carried out by graduate students, in an intellectually stimulating, active research environment.

苜蓿根瘤菌是苜蓿根瘤菌侵染苜蓿根后形成的固氮根瘤。这种植物-微生物相互作用是一个复杂的发育过程，是研究共生固氮的模式系统。我们的研究计划使用细菌遗传工具来研究由ExoS-ChvI转录调控系统控制感染，该系统直接和间接地协调大量基因的表达。我们正在对这种调节系统进行详细的表征，以确定其在控制感染中的作用。DNA结合筛选用于确定该系统直接关闭和打开哪些基因，我们将通过整合Illumina DNA测序技术来改进筛选。我们将尝试确定诱导信号，并且我们还将比较调节系统的突变体的多效性表型与单个靶基因的突变体的表型。我们的工作有可能大大提高我们对感染过程的理解，这不仅会影响农业共生固氮的改进，而且还将通过进一步发展细菌分子遗传学的基础知识，为我们的整体研究计划做出贡献。这项工作将由研究生在激发智力、活跃的研究环境中进行。