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

细菌和真菌病原体对农作物造成重大损失。米黄单胞菌(Xanthomonas Oryzae)水稻白叶枯病是水稻白叶枯病的病原菌，在发展中国家影响产量稳定，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诱导的糖转运蛋白的表达，即糖果。在未受感染的植物中，糖参与了糖从光合作用的叶片转移到根、花粉和种子的过程。XOO通过TAL(转录因子样)效应蛋白直接诱导甜味基因的表达，TAL(转录因子样蛋白)是从细菌注射到叶细胞中的。该团队还表明，通过对宿主中的目标序列进行基因组编辑来影响TAL效应器功能的基因改变可以用来设计病原体抗性。该团队假设，病原体的生长严重依赖于宿主的营养供应，而Xoo专门针对叶细胞释放的糖，为病原体提供碳和能量。他们还假设，这种机制与其他宿主/病原体系统相关。这项工作通过靶向水稻和其他作物中由~20个基因家族编码的甜点，为培育强大和广泛的抗病能力奠定了基础。这些结果有望为持久和广泛的抗性提供洞察力，并对环境和生活质量产生全球影响。该项目获得的见解与水稻的病原菌抗性工程相关，但由于机理的基本性质，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，重点放在生物相互作用、细胞生物学和营养生理学之间的少数群体。这项工作将改善ISU、KSU和卡内基研究所的教育环境。该项目将为本科生提供最新的基因分析和工程工具方面的宝贵经验。

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.