Excellence in Research: Phytohormones and Heat-Induced Loss of Wheat Resistance to Hessian Fly

高温（热应激）会降低植物对昆虫的抵抗力，导致作物产量下降。本研究旨在了解植物激素在小麦（Triticum aestivum）对黑森蝇（Mayetiola destructor）抗性表达中的作用，黑森蝇是北美小麦植株最具破坏性的害虫之一。本研究将采用表型、生化和分子生物学相结合的方法，研究植物激素对植物昆虫对温度变化的抗性敏感性的影响。这一发现将有助于理解温度变化下寄主植物热致抗性丧失的机理以及寄主植物与害虫的协同进化。这项研究的实施将提供一个平台，通过带薪研究实习、生物技术研讨会和将研究方法纳入课堂教学，培训费耶特维尔州立大学（FSU）服务不足人群的本科生进行研究、科学交流和分子生物学技术。这些努力将提高FSU本科生，特别是少数民族学生和/或与军事有关的学生进入研究生/专业学校和STEM劳动力的能力，从而增强社会流动性。此外，本研究结果有可能应用于控制黑森蝇在恶劣环境条件下对小麦作物的危害，以提高农业生产力，粮食安全，并使美国农村社区受益。热应激会损害植物对昆虫的抵抗力。本研究以小麦(Triticum aestivum)-黑蝇（Mayetiola destructor）互作为模型，了解植物激素在热胁迫下寄主植物抗虫性中的作用。本研究的总体假设是植物激素茉莉酸（jasmonic acid， JA）、水杨酸（salicylic acid， SA）、12-氧-植物二烯酸（oxo-phytodienoic acid， OPDA）和生长素影响小麦植株OPDA代谢，从而影响热胁迫下小麦对黑森蝇的抗性。为了验证这一假设，将含有r基因H13的黑森蝇抗性品种“Molly”及其易感近等基因系“Newton”分别置于无毒型GP黑森蝇侵染和热应激以及热应激和外用植物激素的组合下。将采用表型分析、生化和分子分析以及代谢组学方法相结合的方法来实现四个目标：1)确定高温条件下植物激素对小麦抗黑森蝇表型的影响；2)研究热胁迫下植物激素对小麦OPDA代谢的影响；3)研究植物激素对热胁迫下小麦抗/易感黑森蝇基因转录本表达的影响；4)研究热胁迫下植物激素对小麦黑森蝇取食部位脂质和脂肪酸代谢的影响。这一发现将有助于进一步了解植物热致抗性丧失的分子机制以及寄主与寄主在温度变化下的协同进化。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

High temperature (Heat stress) can reduce plant resistance to insects, resulting in decreased productivity of crop plants. This research aims to understand the role of phytohormones on the expression of wheat (Triticum aestivum) resistance to Hessian fly (Mayetiola destructor), one of the most destructive insect pests of wheat plants in North America. In this research, a combination of phenotyping, biochemical, and molecular biology approaches will be deployed to investigate the impact of phytohormones on the sensitivity of plant insect resistance to temperature changes. The findings will contribute to the understanding of the mechanism of heat-induced loss of host plant resistance and co-evolution between host plants and insect pests under changing temperatures. The implementation of this research will provide a platform to train undergraduate students of underserved populations at Fayetteville State University (FSU) in research, scientific communication, and molecular biology techniques via paid research internship, biotechnology workshop, and incorporation of research methodologies into classroom teaching. Such efforts will improve the competency of undergraduate students, especially minority students and/or military-associated students at FSU to enter graduate/professional schools and STEM workforce, and therefore enhance social mobility. Furthermore, findings from this research have the potential to be applied to control Hessian fly damage in wheat crop under stressed environmental conditions to improve agriculture productivity, food security, and benefit the rural community in the US.Heat stress can compromise plant resistance to insects. This proposal aims to understand the role of phytohormones in resistance: (R)-gene-medicated host plant resistance to insects under heat stress using wheat (Triticum aestivum)-Hessian fly (Mayetiola destructor) interaction as a model. The overall hypothesis of this research is that phytohormones jasmonic acid (JA), salicylic acid (SA), 12-oxo-phytodienoic acid (OPDA), and auxin affect OPDA metabolism in wheat plants and influence wheat resistance to Hessian fly under heat stress. To test this hypothesis, ‘Molly’, a Hessian fly resistant cultivar containing the R-gene H13 and its susceptible near-isogenic line ‘Newton’ will be infested by an avirulent biotype GP Hessian fly and subjected to heat stress, and a combination of heat stress and external application of phytohormones, respectively. A combination of phenotyping, biochemical and molecular analyses, and metabolomic approaches will be deployed to achieve four objectives:1) to determine the impact of phytohormones on wheat resistance phenotype to Hessian fly under heat conditions; 2) to demonstrate the impact of phytohormones on OPDA metabolism in wheat plants under heat stress; 3) to examine the impact of phytohormones on transcript expression of wheat genes potentially contributing to wheat resistance/susceptibility to Hessian fly under heat stress; 4) to determine the impact of phytohormones on lipid and fatty acid metabolism at Hessian fly feeding sites in wheat plants under heat stress. The findings will enhance the understanding of the molecular mechanisms of heat-induced loss of plant resistance to insects and co-evolution between host plants and parasites under changing temperatures.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.