Phospholipid Acylation in Cotyledons of Cotton Seedlings

磷脂是所有生物膜的组成部分。细胞膜的磷脂组成是高度可变的。磷脂组成的差异决定了膜的特定性质；它的物理性质和功能。磷脂的再加工，如现有膜中磷脂链的去酰化或酰化，可能是细胞快速调节膜功能以响应不断变化的环境条件（如温度、盐浓度、水活度等）的重要机制。尽管人们对膜脂代谢作为一种抵御环境胁迫的方式的作用越来越感兴趣，但现有膜磷脂的零售机制却很少受到关注。本研究计划的目的是研究支持将酰基部分并入现有植物膜磷脂的生化途径的作用。这是通过一种不同于普通植物生物合成途径的途径来完成的，用于从头合成磷脂。本研究计划的具体目的是描述导致这种不寻常的酰基结合到预成型棉籽膜磷脂中的生化途径，并确定参与该过程的酶。这是一个基础研究项目，旨在确定植物细胞如何有效地调节其膜的化学成分，以抵抗环境中的破坏性变化，如温度、盐浓度、水活性等。虽然环境胁迫对膜形成过程中脂质生物合成的影响已经被研究了一段时间，以解释植物抗性的发展，但现有膜中磷脂化学的变化尚未得到解释。将进行实验以确定植物如何改变膜磷脂的结构并确定所涉及的酶。这项研究将大大增加我们对植物抗逆性调控的认识和能力。＊＊＊

Chapman 9320047 Phospholipids are an integral component of all biological membranes. The phospholipid composition of intracellular membranes is highly variable. Differences in phospholipid composition determine the specific properties of the membrane; its physical properties and its function. Retailoring of phospholipids, such as deacylation or acylation of phospholipid chains in existing membranes, may be an important mechanism that the cell has for rapidly adjusting membrane function in response to changing environmental conditions, such as temperature, salt concentration, water activity, etc. Although there has been growing interest in the role of membrane lipid metabolism as a way to protect against environmental stress, retailoring mechanisms of existing membrane phospholipids has received less attention. The aim of this research program is to examine the role of biochemical pathway(s) that support the incorporation of acyl moieties into existing plant membrane phospholipids. This is accomplished by a pathway different from the ordinary plant biosynthetic pathway for de novo phospholipid synthesis. The specific aim of this research program is to delineate the biochemical pathway(s) leading to this unusual acyl-group incorporation into preformed cottonseed membrane phospholipids and to identify the enzyme(s) involved in the process. %%% This is a basic research project to determine how plant cells can efficiently regulate the chemical composition of their membranes to resist destructive changes in their environment, such as temperature, salt concentrations, water activity, etc. Although the effects of environmental stress on lipid biosynthesis in membrane formation have been a subject of research for some time to explain the development of plant resistance, changes in phospholipid chemistry in existing membranes has not. Experiments will be conducted to determine how plants can change the structure of membrane phospholipids and identify the enzymes involved. This research should significantly increase our understanding and ability to control resistance to environmental stress in plants. ***