Collaborative Research: Lipidomic Profiling, Dynamics, and Functions of Head-group Acylation of Membrane Lipids in Plant Stress Responses

在植物的细胞中，脂质形成膜，将细胞与其环境隔开，并将细胞内的隔室彼此隔开。 这些脂质还具有重要的代谢和信号功能，这些功能现在才被建立起来。 随着植物的发育和暴露于环境信号，膜脂被广泛地化学修饰。 脂质分析的最新进展表明，将脂肪酸添加到膜脂质中，称为极性脂质头基酰化，是一个主要的修饰过程，但对该过程或其生理意义知之甚少。 本项目将探讨头基酰化脂类功能，以提高植物适应环境压力的假设。 为了确定头基酰化在植物处于胁迫下时的作用，将鉴定编码负责头基酰化脂质代谢的酶的基因。 通过检查缺失这些基因和酶的植物，与含有它们的植物进行比较，将确定膜脂质头基酰化在植物胁迫响应中的功能。 这些活动将确定有可能提高植物抗逆性和提高农业生产力和质量的代谢步骤。 相关数据将被纳入植物功能基因组知识库。 此外，这项工作将为博士后学员提供生物统计学、化学和生物学方面的跨学科培训，并将通过与历史悠久的黑人兰斯顿大学的教师导师和本科生合作，扩大代表性不足的群体在研究中的参与。该项目旨在提高目前对膜脂质修饰在产生和维持复杂细胞膜中的作用的理解，并影响有机体的性能。 在整个甘油脂质体的背景下，新的基于质谱的方法将用于识别和表征响应于生物胁迫（假单胞菌感染）和非生物胁迫（磷酸盐缺乏）的脂质头基酰化的变化。 为了鉴定负责头基酰化的基因产物，将获得候选基因的敲除突变体的脂质谱，并与野生型植物的脂质谱进行比较。 胁迫下敲除突变体的功能分析数据将与脂质水平相关，提供有关头基酰化在植物功能中的作用的额外信息。 还将测试将酰化头部基团或头部基团酰化脂质应用于植物的效果。 脂质分析和功能数据将被整合到一个新的代谢数据库中，以扩展代谢网络的知识。

In the cells of a plant, lipids form membranes that separate the cell from its environment and compartments within the cell from one another. These lipids also have crucial metabolic and signaling functions that are only now being established. As plants develop and are exposed to environmental signals, membrane lipids are extensively chemically modified. Recent advances in lipid analysis have revealed that addition of a fatty acid to a membrane lipid, called polar lipid head-group acylation, is a major modification process, but relatively little is known about this process or its physiological significance. This project will address the hypothesis that head-group acylation of lipids functions to improve plant adaptation to environmental stress. To identify the role of head-group acylation when plants are under stress, genes encoding enzymes responsible for head-group-acylated lipid metabolism will be identified. By examining plants that are missing these genes and enzymes, in comparison to plants that contain them, the functions of membrane lipid head-group acylation in plant stress responses will be determined. These activities will identify metabolic steps with potential to enhance stress tolerance in plants and improve agricultural productivity and quality. Relevant data will be integrated into a plant functional genomic knowledge base. Further, the work will provide interdisciplinary training in biostatistics, chemistry, and biology to postdoctoral trainees, and it will broaden the participation of underrepresented groups in research through collaboration with a faculty mentor and undergraduate student at historically black Langston University.This project aims to improve current understanding of the role of membrane lipid modification in producing and maintaining complex cell membranes, and influencing organismal performance. In the context of whole glycerolipidomes, new mass spectrometry-based approaches will be used to identify and characterize changes in lipid head-group acylation in response to a biotic stress, Pseudomonas syringae infection, and an abiotic stress, phosphate deficiency. To identify the gene product(s) responsible for head-group acylation, the lipid profiles of knockout mutants of candidate genes will be obtained and compared to the lipid profiles of wild-type plants. Data from functional analysis of the knockout mutants under stress will be correlated with lipid levels, providing additional information about the roles of head-group acylation in plant function. The effects of application of acylated head groups or head-group acylated lipids to plants also will be tested. Lipid profiling and functional data will be integrated into a novel metabolic database to expand knowledge of metabolic networks.