Minority Postdoctoral Research Fellowship for FY2006

本项目为2006年度少数民族博士后科研资助项目。内生真菌和细菌的共生关系和营养获取策略的研究本研究将利用报告基因技术可视化植物组织内的细菌和真菌（内生菌）之间的相互作用。因此，荧光蛋白将被插入到内生真菌Balansia epichloe和内生细菌Erwinia除草剂中。然后将微生物接种到Panicum sp.的叶子中，荧光显微镜将用于观察微生物在植物组织中的位置，并确定它们是否相互关联。接下来，为了确定微生物之间的联系是否通过增加营养物质的可用性而对其中一方或双方有益，微生物将被用作Panicum叶片细胞间隙中糖的微观生物传感器。将真菌糖反应基因与绿色荧光蛋白（gfp）在质粒上融合，并通过农杆菌介导的转化将其插入epichloe中，制成真菌糖生物传感器。构建的质粒会引起gfp荧光的积累，以响应糖的消耗。荧光强度将用于量化可用糖的量。将真菌生物传感器和先前构建的细菌生物传感器一起或单独接种到Panicum sp.，并比较每种情况下的糖利用度。另一项研究将确定白头草产生的生长素是否会增加Panicum sp.细胞间隙的糖有效性。通过质粒插入诱变制备生长素缺陷突变体，并与野生型生长素产生菌株进行比较。生长素导致的糖利用率的增加将通过比较在感染了生长素缺乏突变体和产生生长素的白藜芦醇生物传感器上观察到的荧光强度来确定。为了成功地进行拟议的调查，熟练掌握一些[分子遗传学]实验技术将被获得。在此奖学金的任期内，罗伯茨博士将在加州大学伯克利分校的Steven Lindow博士的指导下精通分子生物学。在本研究中，她将学习并擅长构建带有报告基因的质粒、诱变和农杆菌介导的转化。获得这些技能将进一步增强她以前的植物微生物研究经验，主要集中在一般研究技术上。作为一名全面发展的研究人员，她将更有能力启动一个积极的研究项目，研究植物与微生物的相互作用，她计划鼓励本科生获得实验室经验。她还想成为有兴趣从事科学事业的学生的导师。此外，她渴望通过分享她在研究项目中获得的知识，成为科学界有成就的一员。

This project is awarded under the Minority Postdoctoral Research Fellowships and Supporting Activities Program for 2006. AN INVESTIGATION OF SYMBIOTIC RELATIONSHIPS AND NUTRIENT ACQUISITION STRATEGIES OF ENDOPHYTIC FUNGI AND BACTERIAThis investigation will utilize reporter gene technology to visualize interactions between bacteria and fungi that live inside of plant tissue (endophytes). Thus, fluorescent proteins will be inserted into the endophytic fungus Balansia epichloe and the endophytic bacterium Erwinia herbicola. The microbes will then be inoculated into leaves of Panicum sp. and fluorescent microscopy will be used to visualize where the microbes reside in the plant tissue and to determine whether they associate with each other. Next, to determine whether the association between the microbes is beneficial to one or both of them by increasing nutrient availability, the microbes will be used as microscopic biosensors of sugars in the intercellular spaces of Panicum leaves. A fungal biosensor of sugar will be made by fusing a fungal sugar-responsive gene to green fluorescent protein (gfp) on a plasmid and inserted into B. epichloe via Agrobacterium-mediated transformation. The constructed plasmid will bring about the accumulation of gfp fluorescence in response to sugar consumption. Intensity of fluorescence will be used to quantify the amount of available sugar. The fungal biosensor and previously constructed bacterial biosensors will be inoculated into Panicum sp. together and separately, and sugar availability in each situation will be compared. An additional study to determine whether auxin production by Balansia epichloe increases sugar availability in the intercellular spaces of Panicum sp. will be conducted. Auxin deficient mutants will be made by the process of plasmid insertion mutagenesis and compared to wild-type auxin producing strains of B. epichloe. Increased sugar availability as a result of auxin will be determined by comparing fluorescence intensity visualized in E. herbicola biosensors in Panicum infected with auxin deficient mutants and auxin producing B. epichloe. In order to successfully conduct the proposed investigation, proficiency in a number of [molecular genetic] experimental techniques will be acquired. During the tenure of this fellowship Dr. Roberts will get well versed in molecular biology, under the mentorship of Dr. Steven Lindow at University of California, Berkeley. Specifically for this study, she will learn and become adept at constructing plasmids with reporter genes, mutagenesis, and Agrobacterium tumefaciens-mediated transformation. Acquisition of these skills will further enhance her previous plant microbe research experience, which focused on general research techniques. As a well-rounded researcher she will be better equipped to start an active research program in plant-microbe interactions where she plans to encourage undergraduates to attain laboratory experience. She also wants to serve as a mentor to students interested in pursuing scientific careers. Moreover, she aspires to be an accomplished member of the scientific community by sharing knowledge gained through her research program.