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

细菌和真菌病原体造成重大的作物损失。水稻黄单胞菌。oryzae （Xoo）是水稻细菌性枯萎病的致病因子，它影响产量的稳定性，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（称为SWEETs）的表达。在未感染的植物中，糖参与了糖从光合作用的叶子到根、花粉和种子的转运。Xoo利用TAL（转录因子样）效应蛋白直接诱导SWEET基因表达，该蛋白从细菌中注入叶细胞。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效应功能的遗传改变可用于设计病原体耐药性。研究小组假设，病原体的生长严重依赖于宿主的营养供应，而Xoo专门针对叶子细胞释放的糖，为病原体提供碳和能量。他们还假设这种机制与其他宿主/病原体系统有关。该研究为利用水稻和其他作物中约20个基因家族编码的糖为靶点，构建强大而广泛的抗病基因奠定了基础。研究结果有望深入了解耐久和广泛的耐药性，并对环境和生活质量产生全球性影响。从该项目中获得的见解与水稻的病原体抗性工程有关，但由于其机制的基本性质，该研究可能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，重点是在有机相互作用、细胞生物学和营养生理学之间的界面上研究少数民族。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基因分析和工程工具的宝贵经验。

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.