Modular biochemical networks of maize anti-pathogen defense defined by integrating synthetic biochemistry, genetics and physiological function

对大多数病虫害有效的作物生化防御机制对农业生产力至关重要。各个品种之间的自然遗传多样性提供了独特的、但未得到充分利用的逆境恢复力。玉米(Zea Mays)是美国最重要的农艺作物，也是遗传多样性最高的作物之一。在概念上，玉米与促进松树伤口愈合的粘性汁液平行，受到被称为二萜类化合物的诱导化学物质的保护，这些化学物质作为抗生素来抑制虫害和疾病。从经验来看，缺乏二萜防御的玉米植株在真菌疾病损害方面表现出戏剧性的增加。目前的项目通过定义玉米二萜防御系统的形成和不同的生物活性来揭示作物抗逆性的机制。已建立的自交系之间的可变化学多样性将被利用来利用最先进的遗传图谱和生化技术来鉴定二萜类生物合成基因和酶功能。整合一系列系统的计算、湿法实验室和基于田间的方法将发现玉米二萜类化合物的生物合成机制、化学结构和生态重要性。这些成果将使在面临提高农业生产力的迫切需要时加强作物保护的新战略成为可能。通过容易获得的食品级真菌激活二萜合成将被开发为高中的教育工具，以培养对植物免疫反应、其农业用途以及生物化学物质对人类的重要性的智力好奇心。该项目将通过发现和利用生化作物防御，并通过使用我们的综合方法实施高中课程学习模块，教授现代STEM概念和技术，从而积极影响社会。生物和非生物应激源的复杂组合可以克服作物防御，促进产量损失。作为全球主要粮食作物，玉米(Zea Mays)含有独特且在很大程度上未被分解的特殊二萜类代谢产物，这些代谢产物通过提供对病原体的定量保护而有助于植物的抗逆性。对玉米生化网络的分子机制有一个基础性的理解和农业应用，这将是进一步优化作物抗逆性的关键。这一合作项目将利用互补的遗传、生化和生态方法，获得控制玉米抗病的专门代谢物的精确机制知识。结合功能基因组学、代谢组学、正向遗传学、DNA合成以及体外和体内蛋白质生物化学的组合方法，将能够快速发现途径以阐明玉米特有的二萜-代谢网络。在明确的途径节点上平行产生和分析玉米突变体将揭示真菌诱导的二萜生物合成与植物对病原菌抗性之间的相互关系。同时，纯化的二萜类化合物与一系列玉米病原菌的体外抗真菌生物测定将阐明二萜类化合物生物活性的结构与功能关系。该项目的跨学科性质为培训博士后、研究生和本科生提供了一个极好的框架，并将利用该项目团队与当地高中教师联系起来，开发课程研究模块，作为一个平台，让高中生参与植物与病原体相互作用的交叉原理。为了在玉米-微生物相互作用和农业创新的交汇处促进研究和教育，这项工作产生的知识、酶/代谢物目录、突变系和培训模块等资源将与科学界广泛共享。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

Crop biochemical defense mechanisms effective against most pests and diseases are essential to agricultural productivity. The natural genetic diversity among individual cultivars provides unique, but underutilized, layers of stress resilience. Maize (Zea mays) is the agronomically most important U.S. crop and among the most genetically diverse. Conceptually parallel to the sticky sap promoting wound healing in pine trees, maize is protected by inducible chemicals, termed diterpenoids, that act as antibiotics to suppress pest attack and disease. Empirically, maize plants lacking diterpenoid defenses display dramatic increases in fungal disease damage. The current project unveils mechanisms of crop stress resilience by defining the formation and diverse bioactivities underlying maize diterpenoid defenses. Variable chemical diversity between established inbred lines will be leveraged to identify diterpenoid-biosynthetic genes and enzyme functions using state-of-the-art genetic mapping and biochemical technologies. Integrating a systematic array of computational, wet-lab and field-based approaches will discover the biosynthetic machinery, chemical structures, and ecological importance of maize diterpenoids. These deliverables will enable new strategies for enhancing crop protection in the face of pressing needs for improving agricultural productivity. The activation of diterpenoid synthesis by readily available food-grade fungi will be developed as an educational tool in high schools to foster intellectual curiosity about plant immune responses, their agricultural use, and the importance of biochemicals to humans. The project will positively impact society by discovering and harnessing biochemical crop defenses and teaching modern STEM concepts and technologies through implementing high school Lesson Study Modules using our integrated approach.Complex combinations of biotic and abiotic stressors can overcome crop defenses and promote yield losses. As the dominant global grain crop, maize (Zea mays) contains unique and largely unresolved specialized diterpenoid metabolites that contribute to plant resilience by conferring quantitative protection against pathogens. A foundational understanding and agricultural application of molecular mechanisms underlying maize biochemical networks will be essential to further optimize crop resilience. This collaborative project will leverage complementary genetic, biochemical and ecological approaches to gain a precise mechanistic knowledge of specialized metabolites governing maize disease resistance. Integrating functional genomics, metabolomics, forward genetics, DNA synthesis, and combinatorial in vitro and in vivo protein biochemical approaches will enable rapid pathway discovery to elucidate maize-specific diterpenoid-metabolic networks. Parallel generation and analysis of maize mutants in defined pathway nodes will unravel the interrelations between fungal-elicited diterpenoid biosynthesis and pathogen resistance in planta. In tandem, in vitro anti-fungal bioassays of purified diterpenoids with a range of maize pathogens will illuminate the structure-function relationships underlying diterpenoid bioactivity. The cross-disciplinary nature of this project provides an excellent framework for training postdoctoral, graduate and undergraduate students, and will be leveraged to connect the project team with local high school teachers for developing Lesson Study Modules as a platform to engage high school students in cross-cutting principles underlying plant-pathogen interactions. To promote research and education at the confluence of maize-microbe interactions and agricultural innovation, knowledge, resources such as enzyme/metabolite catalogs, mutant lines, and training modules arising from this work will be broadly shared with the scientific community.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.