RUI: Regulation of natural variation in maize (Zea mays) defense responses by jasmonate signaling

每年，全球农业由于虫害的袭击而遭受重大的产量损失。据估计，美国因虫害损失了25-30%的农业产量，而热带国家的估计高达50%。昆虫喂养造成的损失和减少这种损失的方法的实施每年花费美国农民约400亿美元。然而，所有植物都有不同程度的天然保护，以防止昆虫植食性，包括机械屏障，如毛和刺和化学防御，阻止或杀死害虫。此外，植物可以发出不稳定的信号来招募捕食者，以消耗攻击昆虫。虽然有些防御措施总是存在的，但其他防御措施只有在植物检测到昆虫进食时才会打开。这种防御诱导是由一种在植物界高度保守的激素信号传导途径协调的。这项研究的重点是识别和研究玉米防御信号通路的新成分，玉米是美国最重要的粮食作物。鉴定玉米抗虫性的自然变异将为培育更耐受害虫的植物提供新的机会。此外，该项目将为本科生提供真实的研究经验，包括来自科学代表性不足的群体的学生。该项目的一个拟议外联部分将使更广泛的社区了解植物-昆虫相互作用的研究。茉莉酸信号级联调控植物对昆虫攻击的转录组反应，影响成千上万个基因的表达。尽管玉米（Zea mays）作为作物物种的全球重要性和茉莉酸在调节植物防御反应中的关键作用，但与充分研究的模式植物物种如拟南芥和番茄中的相应途径相比，玉米茉莉酸信号级联仍然相对未被研究。考虑到这些模式双子叶植物和玉米之间的进化距离，这是合理的，预期不同的茉莉酸调控机制，在防御反应的经济上重要的单子叶植物物种。一个综合的系统生物学方法，包括转录组学，代谢组学和遗传学方法，将被用来发现和表征玉米防御调控的新方面。一个遗传多样性的人口玉米自交系将被用来评估自然变化的积累，草食动物诱导的茉莉酸酯和茉莉酸酯样分子，确定以前未知的调节防御反应，并阐明其在玉米防御两个鳞翅目害虫，秋粘虫（草地贪夜蛾）和甜菜粘虫（甜菜夜蛾）的作用。除了为科学界提供玉米防御反应调控的见解外，计划中的研究还将产生高质量的转录组学和代谢组学数据集，使其他研究人员能够进一步研究玉米防御反应的自然变异。一名研究生和一名博士后将接受研究培训，并将通过帮助监督为该项目做出贡献的本科生的实验来获得指导经验。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。

Each year, global agriculture suffers significant yield losses due to attack by insect pests. The United States is estimated to lose 25-30% of its agricultural production to insect attack, while estimates for tropical countries are as high as 50%. Damage from insect feeding and implementation of methods to reduce this damage cost American farmers about $40 billion annually. However, all plants have varying levels of natural protection against insect herbivory, including both mechanical barriers such has hairs and thorns and chemical defenses that deter or kill insect pests. Additionally, plants can emit volatile signals to recruit predators that consume the attacking insects. Although some defenses are always present, others are turned on only when the plants detect insect feeding. This defense induction is orchestrated by a hormone signaling pathway that is highly conserved in the plant kingdom. The proposed research is focused on identifying and investigating novel components of the defense signaling pathway in maize, the most important food crop in the United States. The identification of natural variation in the resistance of maize to insect feeding will provide new opportunities for breeding plants that are more pest tolerant. In addition, the project will provide authentic research experiences to undergraduate students, including students from groups that are underrepresented in science. A proposed outreach component of the project will expose the broader community to research on plant-insect interactions. The jasmonic acid signaling cascade, which regulates the transcriptomic responses of plants to insect attack, influences the expression of thousands of genes. Despite the global importance of maize (Zea mays) as a crop species and the critical role of jasmonates in regulating plant defense responses, the maize jasmonic acid signaling cascade remains relatively uninvestigated compared to the corresponding pathways in well-studied model plant species such as Arabidopsis and tomato. Considering the evolutionary distance between these model dicots and maize, it is reasonable to expect distinct jasmonic acid regulatory mechanisms in the defense responses of this economically important monocot species. An integrated systems biology approach, involving transcriptomic, metabolomic, and genetic methods, will be used to uncover and characterize novel aspects of defense regulation in maize. A genetically diverse population of maize inbred lines will be used to assess natural variation in the accumulation of herbivore-induced jasmonate and jasmonate-like molecules, identify previously unknown regulators of defense responses, and elucidate their roles in maize defense against two lepidopteran pests, fall armyworms (Spodoptera frugiperda) and beet armyworms (Spodoptera exigua). In addition to providing the scientific community with insight into the regulation of defense responses in maize, the planned studies will generate high-quality transcriptomic and metabolomic data sets that will enable other researchers to conduct further investigations of natural variation in maize defense responses. A graduate student and a postdoc will receive research training and will gain mentoring experience by helping to supervise the experiments of undergraduate students contributing on this project.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.