EAGER: Striga Virulence Effectors: Keys to Halting Parasitic Witchweeds

EAGER：独脚金毒力效应器：阻止寄生巫草的关键

• 批准号: 1213059
• 负责人: Michael Timko
• 金额: $ 29.9万
• 依托单位: University of Virginia Main Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-15 至 2016-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1213059&HistoricalAwards=false
• 关键词: EAGER; Striga; Virulence; Effectors; Keys

Parasitic angiosperms are noxious and persistent pests in farmers' fields and serious constraints to crop productivity. The "witchweeds", members of the genus Striga, are particularly devastating since their primary hosts include the major cereals (maize, sorghum, rice and millet) and grain legumes that are dietary staples worldwide. How parasitic weeds and Striga species in particular recognize their potential hosts and overcome the innate defense systems are not known. Using the interaction of cowpea (Vigna unguiculata), an important food and forage legume, with Striga gesnerioides, this project seeks to identify parasite-derived effectors and virulence proteins that enter host cells, specifically altering their structure and function and suppressing the defense response mechanism at various levels, enabling infection and parasite ingress to occur. Novel, in planta functional screens will be used to identify candidate effectors from Striga that are directly or indirectly recognized by race-specific resistance proteins in cowpea leading to activation of a hypersensitive response at the point of infection and associated downstream defense responses. These functional screens are complemented by comparative transcriptome sequencing in compatible and incompatible host-parasite association and in silico analysis aimed at identifying candidate virulence effectors through race-specific gene expression signatures. The outcomes of this project will provide novel insights into the mechanisms by which parasitic angiosperms identify and parasitize their hosts and how hosts block such attack. The negative impact of parasitic plants on crop productivity increases globally each year and their potential for affecting domestic agriculture looms larger as the movement of seed resources expands globally. The outcomes of this work will contribute directly to the development of strategies to improve crop security by providing targets for manipulating pest resistance responses of crop plants. In addition these studies provide new educational, research, and training opportunities for US students on the African continent.

寄生被子植物是农民田地上的一种有害且持久的害虫，严重制约着作物产量。“独脚金”属植物具有特别的破坏性，因为它们的主要寄主包括世界各地的主要谷物(玉米、高粱、水稻和谷子)和作为主食的谷物豆类。尤其是寄生杂草和斯特里加物种如何识别它们的潜在宿主并克服固有的防御系统尚不清楚。利用重要的食用和饲用豆类豌豆(Vigna Unguulata)与Gesnerioides的相互作用，该项目试图识别进入宿主细胞的寄生虫衍生的效应物和毒力蛋白，特别是改变它们的结构和功能，并在不同水平上抑制防御反应机制，使感染和寄生虫入侵发生。新颖的是，在Planta中，功能筛选将被用于从Striga中识别直接或间接识别的候选效应物，这些效应物可由豌豆中的小种特异性抗性蛋白识别，从而激活侵染点的过敏性反应和相关的下游防御反应。这些功能筛选的补充是在相容和不相容的宿主-寄生虫联合中的比较转录组测序，以及旨在通过小种特异性基因表达特征识别候选毒力效应的电子分析中。该项目的成果将为寄生被子植物识别和寄生宿主的机制以及宿主如何阻止这种攻击提供新的见解。寄生植物对作物生产力的负面影响在全球范围内每年都在增加，随着种子资源在全球范围内流动的扩大，它们影响国内农业的可能性越来越大。这项工作的成果将通过提供操纵作物抗虫性反应的目标，直接有助于制定改善作物安全的战略。此外，这些研究还为非洲大陆的美国学生提供了新的教育、研究和培训机会。