Essential Nature of Fatty Acid Elongation in Plant Development

超长链脂肪酸(VLCFA)是一种含有20个或更多碳单元的脂肪酸，它被结合到各种具有重要生理意义的植物化学物质中，包括角质蜡、角质、黄麻素、鞘磷脂以及一些磷脂和种子油。编码与VLCFAs生产有关的几种酶的基因已经被分离出来。根据这一发现，阻断这些酶的产生的玉米突变体对胚胎是致命的，VLCFAs在玉米胚胎发生过程中肯定是必不可少的。因此，阻断必需VLCFA积累的突变体提供了一个理想的实验系统来确定VLCFA衍生的植物化学物质在植物发育中的基本作用。拟议的项目将通过确定区分突变胚胎和正常胚胎的形态差异来定义VLCFA的基本发育作用(S)。它还将通过比较VLCFA衍生化合物在正常和突变胚胎中的积累，确定哪些VLCFA衍生化合物(S)在胚胎发育过程中是必不可少的。最后，将分离出在生产VLCFA过程中克服与遗传块相关的胚胎致命性的突变株。从长远来看，这些突变体可以用来剖析利用VLCFAs的不同生化途径网络。拟议的研究通过继续利用整合了遗传和生化方法的长期研究合作所固有的协同作用，迎接了理解生物化学和发育之间复杂相互作用的挑战。该项目将为不同的早期科学家群体提供出色的跨学科培训经验，因为它将使用假设驱动和全基因组分析的组合，并应用尖端技术来解决植物生物学中已被证明不愿采用单一学科方法的重大问题。

Very long chain fatty acids (VLCFAs), those that contain 20 or more carbon units, are incorporated into a wide variety of physiologically significant phytochemicals, including cuticular waxes, cutin, suberin, sphingolipids, and some phospholipids and seed oils. Genes that encode several of the enzymes involved in the production of VLCFAs have been isolated. Based on the finding that maize mutants that block the production of one of these enzymes are embryo lethal, VLCFAs must be essential during maize embryogenesis. Mutants that block the accumulation of essential VLCFAs therefore provide an ideal experimental system to determine the essential role of VLCFA-derived phytochemicals in plant development.The proposed project will define the essential developmental role(s) of VLCFAs, by determining the morphological differences that distinguish the development of mutant embryos from normal embryos. It will also establish which VLCFA-derived compound(s) are essential during embryo development, by comparing the accumulation of VLCFA-derived compounds in normal and mutant embryos. Finally, mutants that overcome the embryo lethality associated with genetic blocks in the production of VLCFAs will be isolated. In the long term, these mutants can be used to dissect the diverse network of biochemical pathways that utilize VLCFAs.The proposed studies meet the challenge of understanding the complex interplay between biochemistry and development by continuing to exploit the synergy inherent in a long-term research collaboration that integrates genetic and biochemical approaches. This project will provide excellent cross-disciplinary training experiences to a diverse group of early-career scientists because it will use a combination of hypothesis-driven and genome-wide analyses, and apply cutting-edge technologies to address significant questions in plant biology that have proven recalcitrant to a mono-disciplinary approach.