The function of lipid flippases in plant growth and thermotolerance

脂质翻转酶在植物生长和耐热性中的功能

• 批准号: 2129234
• 负责人: Jeffrey Harper
• 金额: $ 101.69万
• 依托单位: Board of Regents, NSHE, obo University of Nevada, Reno
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-15 至 2026-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2129234&HistoricalAwards=false
• 关键词: function; lipid; flippases; plant; growth

A broader impact objective of this project is to develop crop plants that are more tolerant to heat stress. Climate change is expected to result in more frequent and severe periods of heat stress that will significantly reduce yields from agricultural crops. Simultaneously, projections indicate that world-wide food production must increase by more than 70% to feed an expected increase in the global human population to 10 billion by 2057. To meet the growing food demands it is critical that we develop crop plants that are more tolerant to heat stress conditions (i.e., the new normal). The proposed project aims to better understand how plants remodel their lipid membranes during heat stress, with a specific focus on a family of enzymes that flip lipids across membranes (lipid flippases). The research goals include engineering selected lipid flippases to be more active and testing whether these modified enzymes can accelerate the rate in which plants remodel their membranes to cope with changing temperatures. The research will determine whether this “faster membrane remodeling” strategy has any positive effect on plant growth, fertility, and seed yield under heat stress conditions. If successful, this technology could be applied to crop species and potentially improve yields under heat-stress conditions, thus strengthening global food-security in a warming world. Additionally, the research will provide a venue for teams of undergraduate student researchers to gain in-depth research experience in the field of plant biology. The long-term scientific goal is to understand the cellular functions of lipid flippases in eukaryotic cells and to use that knowledge to develop strategies to make crop plants more climate resilient. In plants, lipid flippases are referred to as ALAs (Aminophospho-Lipid ATPases, or P4-type ATPases) and these enzymes utilize ATP hydrolysis to catalyze the flipping of specific lipids from one side of the membrane to the other. Genetic knockouts of several ALAs in Arabidopsis result in plants that are hypersensitive to temperature changes. The central hypothesis guiding the research is that lipid flippases play critical roles in the rapid remodeling of membranes in response to changing temperatures. The first aim is to use domain swapping and site specific mutagenesis to identify important regulatory features within different ALAs. A key hypothesis to be tested is that variations in the C-terminal domain confer specific cellular functions, either by changing an ALA’s activity, regulation, localization, or substrate specificity. The second aim is to use lipidomics to quantify the abundance of specific lipids and determine whether a temperature-sensitive ala3 mutant has a defect in lipid remodeling during hot and cold temperature stresses. The third aim will determine whether the expression of a hyperactive ALA can improve vegetative growth or reproductive fitness under heat-stress conditions. The practical focus is to use recently gained knowledge on the C-terminal regulatory domains of ALAs to develop a novel strategy for improving thermotolerance in crop plants.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.

该项目的一个更广泛的影响是开发更宽容的作物植物。预计气候变化会导致更频繁的热应激时期，这将显着降低农作物的产量。同时，项目表明，到2057年，全球粮食产量必须增加70％以上，以养活全球人口的预期增加到100亿。为了满足不断增长的粮食需求，至关重要的是，至关重要的是，我们至关重要的是，我们开发对热应激状况更耐受的作物植物（即新常态）。拟议的项目旨在更好地了解植物在热应激期间如何重塑其脂质膜，并特别关注将脂质翻转的酶家族（脂质氟）。研究目标包括工程选定的脂质爆破酶更为活跃，并测试这些改良的酶是否可以加速植物重塑其机制以应对温度变化的速度。该研究将确定这种“更快的膜重塑”策略是否对热应激条件下的植物生长，生育能力和种子产量有任何积极影响。如果成功的话，该技术可以应用于作物物种，并可能在热应力条件下提高产量，从而加强在变暖世界中的全球粮食安全。此外，该研究将提供一个场地。让本科生研究人员团队获得植物生物学领域的深入研究经验。长期的科学目标是了解真核细胞中脂质氟酶的细胞功能，并利用这些知识来制定策略，使作物植物更具气候弹性。在植物中，脂质氟酶被称为alas（氨基磷 - 脂质ATPase或P4型ATPases），这些酶利用ATP水解将特定脂质从膜的一侧催化到另一个。拟南芥中几种ALA的​​遗传敲除导致对温度变化过敏的植物。指导研究的中心假设是，脂质爆裂酶在响应变化的温度时在膜的快速重塑中起关键作用。第一个目的是使用域交换和特定于现场的诱变来识别不同ALA中的重要调节特征。要测试的关键假设是，通过改变ALA的活动，调节，定位或底物特异性，C末端域会议特定细胞功能的变化。第二个目的是使用脂质来量化特定脂质的丰度，并确定对温度敏感的ALA3突变体在热和冷温度应力期间是否具有脂质重塑缺陷。第三个目标将决定过度活跃的ALA的表达是否可以改善热压力条件下的营养生长或生殖适应性。实用的重点是使用最近获得有关C末端监管领域的知识，以制定一种新的策略来改善作物植物的耐热性。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛的影响标准通过评估来评估的。

项目成果

Investigation of the biochemical controls on mercury uptake and mobility in trees

树木汞吸收和迁移的生化控制研究

• DOI: 10.1016/j.scitotenv.2022.158101
• 发表时间: 2022
• 期刊: Science of The Total Environment
• 影响因子: 9.8
• 作者: Gustin, Mae Sexauer;Dunham-Cheatham, Sarrah M.;Harper, Jeffrey F.;Choi, Won-Gyu;Blum, Joel D.;Johnson, Marcus W.
• 通讯作者: Johnson, Marcus W.

Resting cytosol Ca2+ level maintained by Ca2+ pumps affects environmental responses in Arabidopsis

Ca2泵维持的静息细胞质Ca2水平影响拟南芥的环境反应

• DOI: 10.1093/plphys/kiad047
• 发表时间: 2023
• 期刊: Plant Physiology
• 影响因子: 7.4
• 作者: Li, Zhan;Harper, Jeffrey F.;Weigand, Chrystle;Hua, Jian
• 通讯作者: Hua, Jian

Disruption of pollen tube homogalacturonan synthesis relieves pollen tube penetration defects in the Arabidopsis O-FUCOSYLTRANSFERASE1 mutant

• DOI: 10.1007/s00497-023-00468-5
• 发表时间: 2023-05
• 期刊: Plant Reproduction
• 影响因子: 3.4
• 作者: Kayleigh Robichaux;Devin K. Smith;Madison Blea;Chrystle Weigand;J. Harper;I. Wallace