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

在植物细胞中，脂类形成膜，将细胞与环境隔开，细胞内的隔间相互隔开。这些脂质还具有关键的代谢和信号功能，这些功能直到现在才被确立。随着植物的发育和暴露在环境信号中，膜脂被广泛的化学修饰。脂类分析的最新进展表明，在膜脂上加成一种脂肪酸，称为极性脂头基酰化，是一种主要的修饰过程，但人们对这一过程及其生理意义知之甚少。这个项目将解决这一假设，即头基团的脂酰化功能，以改善植物对环境胁迫的适应。为了确定植物在逆境下头基酰化的作用，将识别编码负责头基酰化脂肪代谢的酶的基因。通过检查缺少这些基因和酶的植物，与含有这些基因和酶的植物相比，膜脂头基酰化在植物胁迫反应中的功能将被确定。这些活动将确定具有增强植物抗逆性和提高农业生产力和质量的潜在代谢步骤。相关数据将整合到植物功能基因组知识库中。此外，这项工作将为博士后实习生提供生物统计学、化学和生物学方面的跨学科培训，并将通过与历史上黑人的兰斯顿大学的教师导师和本科生合作，扩大未被充分代表的群体参与研究的范围。该项目旨在提高目前对膜脂修饰在生产和维护复杂细胞膜以及影响机体表现方面的作用的理解。在整个甘油脂体的背景下，新的基于质谱学的方法将被用来识别和表征响应生物胁迫(丁香假单胞菌感染)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(S)，我们将获得候选基因敲除突变体的脂谱，并将其与野生型植物的脂谱进行比较。基因敲除突变体在胁迫下的功能分析数据将与血脂水平相关，从而提供有关头基酰化在植物功能中的作用的更多信息。还将测试在植物上应用酰化头基或头基酰化脂的效果。脂谱和功能数据将被整合到一个新的代谢数据库中，以扩大代谢网络的知识。

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.