CAREER: Chemosensory Behavior in Plant-Microbe Association

固氮菌Azoacellum brasilense在植物根表的定殖可能依赖于对根系分泌物的趋化性。然而，大多数植物相关细菌的化学感受行为的分子机制仍然知之甚少。本研究的重点是建立A. brasilense及其在小麦根系定殖中的作用首先，将阐明中央趋化性调节剂CheA的独特保守结构域在感知和行为中的功能（研究目标1）。接下来，将确定新的化学感受器在行为中的功能（研究目标2）。最后，一般的趋化性机械和个人的化学感受器在建立的固氮小麦协会的贡献将被确定（研究目标3）。这项研究的结果将增进对原核生物信号转导多样性的理解，并直接有益于生物肥料设计领域。所获得的结果可用于开发具有改进的定殖在农学上重要的植物（例如小麦）的根际的能力的菌株。细菌的传感和行为非常适合扩大大学生的教育经验，并为K-12学生开发基于研究的教育材料。本科生（教育目标1）和K-12科学教师（教育目标2）将在正在进行的项目中提供研究机会。将在国家科学基金会资助的生物巴士项目中实施一个关于“微生物传感”的单元，为格鲁吉亚的K-12学生提供探究式学习机会和动手实验（教育目标3）。

The colonization of the plant root surface by the plant-growth promoting nitrogen-fixing bacterium Azospirillum brasilense is likely to be dependent on chemotaxis toward root exudates. However, the molecular mechanisms governing chemosensory behavior in most plant-associated bacteria are still poorly understood. This research project focuses on establishing the molecular basis of the chemosensory behavior in A. brasilense and its role in wheat root colonization. First, the function of the unique conserved domain of the central chemotaxis regulator CheA in sensing and behavior will be elucidated (research objective 1). Next, the function of novel chemoreceptors in behavior will be identified (research objective 2). Finally, the contribution of the general chemotaxis machinery and individual chemoreceptors in the establishment of the Azospirillum-wheat association will be determined (research objective 3). The outcome of the proposed research will enhance understanding of diversity in signal transduction in prokaryotes and directly benefit the field of biofertilizer design. The results obtained can be used for developing strains with improved abilities to colonize the rhizosphere of agronomically important plants, such as wheat. Sensing and behavior in bacteria are uniquely suited for broadening the educational experience of college students and enable the development of research-based educational materials for K-12 students. Undergraduate students (education objective 1) and K-12 science teachers (education objective 2) will be provided with research opportunities in the ongoing project. A module on "Microbial Sensing" will be implemented in the NSF-funded Bio-Bus project that provides inquiry-based learning opportunities and hands-on experiments to Georgia's K-12 students (education objective 3).