Role of Oxalic Acid and Reactive Oxygen in Sclerotinia Sclerotiorum Disease Development

智力优势 核盘菌（Sclerotinia sclerotiorum）是一种杂食性真菌植物病原体，具有极其广泛的宿主范围，能够在经济上重要的粮食作物中产生毁灭性的损失，包括大豆、干豆、油菜和马铃薯等。 超过400种植物对这种病原体敏感。 目前，还没有足够的抗核盘菌属疾病的抗性策略（文化或化学），对这种真菌的抗性育种也没有成功。 每年由S.在美国，核盘菌的价格在数百万美元的范围内。 核盘菌属具有侵略性，寄主范围广，防治效果差，造成重大经济损失，加上缺乏抗性品种，因此需要开发替代防治策略。 在这个项目中将使用一种基于分子的机制方法来理解真菌为什么如此成功;特别是该项目将研究活性氧和草酸作为真菌疾病的关键调节剂所起的作用。 最近的观察表明，真菌分泌的草酸盐诱导植物宿主细胞程序性死亡，并重演了S。菌核病症状。 类似地，草酸诱导植物中活性氧水平增加，这与程序性细胞死亡和疾病相关并且是程序性细胞死亡和疾病所必需的。 这些研究的结果将为基于干扰这些关键真菌致病性决定因素的替代疾病控制策略提供信息。 本项目中所描述的实验为学生提供了广泛而全面的培训，涵盖了许多领域。目前的方法包括微生物学、植物病理学、植物生物学、高通量基因沉默筛选、分子生物学和遗传学。真菌诱导植物病害的机制是基础性的，也是重要的。这一点特别值得注意，因为食品安全、食品污染和食品保障是国家和国际上的重要问题。由于控制措施（遗传和化学）基本无效，这与核盘菌病有关。该研究计划将为研究生，博士后研究员和本科生提供一个独特的跨学科培训机会，参与应激信号传导和细胞死亡调节的关键领域，同时从概念上解决更广泛的概念性想法，以了解这一特定的重要植物病原体如何取得致病性成功。 该项目还支持来自西班牙裔服务机构和得克萨斯州赠地大学的学生的夏季研究活动。

Intellectual Merit Sclerotinia sclerotiorum is an omnivorous fungal plant pathogen with an extremely broad host range capable of producing devastating losses in economically important food crops, including soybeans, dry beans, canola and potato among many others. Over 400 species of plants are susceptible to this pathogen. Currently, there are no adequate resistance strategies against Sclerotinia diseases (culturally or chemically) and breeding for resistance to this fungus has not been successful. Annual losses of crops from diseases caused by S. sclerotiorum in the U.S. are in the multimillion dollar range. The fact that Sclerotinia is aggressive, broad in its host range, poorly controlled and causes significant economical damage, coupled with the lack of resistant cultivars necessitates the development of alternative control strategies. A molecular based mechanistic approach will be used in this project to understand why the fungus is so successful; in particular the project will examine the roles that reactive oxygen species and oxalic acid play as key modulators of fungal disease. The project is supported by recent observations that demonstrated that fungal secreted oxalate induces a programmed cell death in the plant host and recapitulates S. sclerotiorum disease symptoms. Similarly oxalic acid induces increased reactive oxygen species levels in the plant which correlate with, and are necessary for, programmed cell death and disease. Results from these studies will provide information for alternative disease control strategies based on interference with these key fungal pathogenicity determinants.Broader Impact The experiments described in this project offer broad and comprehensive training for students encompassing a number of fields. Current approaches include microbiology, plant pathology, plant biology, high throughput gene silencing screens, molecular biology and genetics. The mechanisms underlying fungal induced plant disease are both fundamental and of practical importance. This is particularly noteworthy since food safety, food contamination and food security are critically important issues nationally and internationally. This is compounded by Sclerotinia diseases since control measures (genetic and chemical) are largely ineffective. This research program will provide a unique and interdisciplinary training opportunity for a graduate student, postdoctoral fellows, and undergraduate students to participate in a critical area of stress signalling and cell death regulation, while conceptually addressing broader conceptual ideas as to how this particular group of important plant pathogens achieves pathogenic success. The project also supports summer research activities for students from Hispanic Serving Institutions and a Land Grant University in Texas.