CAREER: Understanding non-photochemical quenching under chilling in the warm-season C4 grasses

该奖项全部或部分由《2021年美国救援计划法案》（公法117-2）资助。对低温的敏感性极大地限制了作物的分布、建立和生产力。经济上重要的禾草，如玉米和甘蔗，起源于温暖的气候，没有发展出防寒的措施。在低温下，叶片吸收的太阳能大大超过其用于二氧化碳固定的能量，从而导致氧化应激和随后的光损伤，生长受阻，最终导致植物死亡。作为一种光保护反应，叶子会切换到“安全模式”，在这种模式下，多余的能量可以无害地释放出来。在寒冷条件下，人们对温暖气候中的这些保护开关知之甚少。因此，本项目将结合生理学、生物化学、遗传学、代谢组学和田间表型组学，揭示低温胁迫下氧化应激的保护机制调控。提高温暖气候作物的耐寒性将增加其气候适应能力，使其能够提前春季播种/再生，从而延长生长季节，同时促进对早期土壤水分的更多利用。教育部分将培养本科生终身的科学传播技能。这些研究经历将为女性本科生和研究生以及一名博士后提供工具性培训。女性在STEM领域的更多参与将导致一支更多样化、更强大的科学队伍。公众外展活动将旨在提高对养活世界的研究创新的接受和赞赏。本研究旨在了解C4暖季禾本科植物在低温条件下的非光化学猝灭（NPQ）机制。这项研究将在芒草上进行，芒草是玉米和甘蔗的近亲，同时也具有极强的低温耐受性。芒草广泛的地理分布为阐明C4光合耐寒的潜在机制提供了独特的机会。通过跨越生物组织水平，本项目将：1)定义NPQ的低温依赖特性及其对植物生理的影响；2)确定关键的NPQ相关基因如何影响NPQ特性的冷光依赖性和非依赖性变化；3)确定NPQ如何在整个有机体的层面上整合。本研究整合了以下教育目标：4)开发和传播本科水平的课程，提高学生的科学沟通能力；5)通过实践活动让女孩参与植物科学；6)教育和让公众参与光合作用及其在作物物种中的潜在改进。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。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).Sensitivity to low temperatures greatly limits the distribution, establishment, and productivity of crops. The economically important grasses such as maize and sugarcane originated in a warm climate and did not develop protection against cold. In low temperatures, solar energy absorbed by leaves exceeds greatly its use for CO2 fixation, which leads to oxidative stress and subsequent photodamage, arrest of growth and eventually plant death. As a photoprotective response, the leaf switches into a ‘safety mode’ where an excess of energy can be harmlessly released. Little is known about these protective switches in warm climate grasses under cold conditions. Therefore, this project integrates physiology, biochemistry, genetics, metabolomics and field phenomics to reveal the regulation of protective mechanisms against oxidative stress under chilling and cold. Improved chilling tolerance of warm climate crops would increase their climate resilience, enable an earlier spring planting/regrowth that would extend the growing season while facilitating increased use of early season soil-moisture. The education component will train undergraduate students on the life-long skill of science communication. The research experiences will provide instrumental training to female undergraduate and graduate students, and a postdoctoral fellow. Increased participation of women in STEM will lead to a more diverse and stronger scientific workforce. The public outreach activities will aim for higher acceptance and appreciation for research innovation in feeding the world.The research goal of this proposal is to understand the non-photochemical quenching (NPQ) mechanism under chilling in C4 warm-season grasses. The study will be performed on Miscanthus, which is a close relative to maize and sugarcane while being also extremely tolerant to low temperatures. The extensive geographical distribution of Miscanthus offers unique opportunities to elucidate the underlying mechanisms of C4 photosynthesis tolerance to chilling. By spanning across levels of biological organization this project will 1) Define chilling-dependent characteristics of NPQ and their effect on plant physiology; 2) Identify how key NPQ related genes contribute to chilling light-dependent and -independent changes in NPQ characteristics; 3) Determine how NPQ is integrated at the level of the whole organism. The following education objectives are integrated with the research: 4) Develop and disseminate an undergraduate-level course to increase students’ science communication skills; 5) Engage girls in plant science via hands-on activities; and 6) Educate and engage the public on photosynthesis and its potential improvement in crop species.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.