Collaborative Research: The role of host nutrient carriers in pathogen susceptibility

细菌和真菌病原体造成主要作物损失。黄单胞菌黄单胞菌致病型（Xanthomonasandrogpv.）水稻白叶枯病的病原菌Xoo影响产量稳定性，在发展中国家损失高达60%。三个具有互补专业知识的小组已经确定了植物疾病易感性的基本机制，涉及Xoo诱导的糖转运蛋白（SWEET）的表达。在未感染的植物中，SWEET参与了糖从光合作用的叶子到根、花粉和种子的转运。Xoo使用TAL（转录因子样）效应蛋白直接诱导SWEET基因表达，TAL效应蛋白从细菌注射到叶细胞中。该团队还表明，通过宿主中靶序列的基因组编辑影响TAL效应器功能的遗传改变可用于工程病原体抗性。该团队假设病原体的生长严重依赖于宿主的营养供应，并且Xoo专门针对叶细胞的糖释放，为病原体提供碳和能量。他们还假设这种机制与其他宿主/病原体系统有关。这项工作为通过靶向由水稻和其他作物中约20个基因家族编码的SWE 1基因来工程化强大和广泛的抗病性奠定了基础。这些结果有望为持久和广泛的抗性提供见解，并对环境和生活质量产生全球影响。从该项目中获得的见解与水稻的病原体抗性工程有关，但由于该机制的基本性质，该研究可能会对其他作物产生影响。该项目将为高中生、本科生和研究生以及博士后提供培训，重点是在生物体相互作用、细胞生物学和营养生理学之间的界面上的少数民族。这项工作将改善国际空间大学、堪萨斯州立大学和卡内基研究所的教育环境。该项目将为本科生提供遗传分析和工程最新工具的宝贵经验。

Bacterial and fungal pathogens inflict major crop losses. The bacterium Xanthomonas oryzae pv. oryzae (Xoo), the causal agent for bacterial blight of rice, affects yield stability with losses up to 60% in the developing world. Three groups with complementary expertise have identified a fundamental mechanism for plant disease susceptibility involving Xoo-induced expression of sugar transporters known as SWEETs. SWEETs are involved in the translocation of sugars from photosynthetic leaves to roots, pollen, and seeds in uninfected plants. Xoo directly induces SWEET gene expression using TAL (transcription factor-like) effector proteins, which are injected from bacterium into leaf cells. The team has also shown that genetic alterations affecting TAL effector function through genomic editing of the target sequence in the host can be used to engineer pathogen resistance. The team hypothesizes that growth of the pathogen depends critically on nutrient supply from the host, and that Xoo specifically targets sugar release from leaf cells for supplying carbon and energy to the pathogen. They also hypothesize that this mechanism is relevant for other host/pathogen systems. This work lays the basis for engineering robust and broad disease resistance by targeting SWEETs encoded by a family of ~20 genes in rice and other crops. The results are expected to provide insight into durable and broad resistance and have global impacts on the environment and quality of life.The insights gained from this project are relevant to engineering pathogen resistance in rice, but due to the fundamental nature of the mechanism the research may have impact in other crops. The project will provide training for high-school, undergraduate and graduate students, and postdocs with an emphasis on minorities at the interface between organismal interactions, cell biology and nutrition physiology. The work will enhance the educational environments at ISU, KSU, and the Carnegie Institution. The project will provide undergraduates with valuable experience in the latest tools of genetic analysis and engineering.