Biosynthesis of plant cuticular wax components

植物角质层蜡成分的生物合成

• 批准号: 327061-2006
• 负责人: Rowland, Owen
• 金额: $ 2.7万
• 依托单位: Carleton University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2008
• 资助国家: 加拿大
• 起止时间: 2008-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=397553
• 关键词: Biosynthesis; plant; cuticular; wax; components

All land plants are coated with a waxy "skin" called the cuticle that serves as a protective barrier against water loss, UV light, pathogens, and insects.  The cuticle is comprised primarily of lipids in the form of cutin and waxes.  Intracuticular waxes are embedded in the three-dimensional cutin matrix whereas epicuticular waxes, often in crystalline form, cover the outer surface.        The overall goal of our research program is to understand how cuticular waxes are synthesized and then deposited on the surfaces of plants.  Genetic studies indicate that a large number of proteins participate in cuticular wax production, but only a handful of these have been identified.  We are taking advantage of wax-deficient or 'cer' mutants in the model plant Arabidopsis thaliana to identify and functionally characterize gene products involved in wax biosynthesis and deposition.  We have recently identified CER4, which encodes an alcohol-forming fatty acyl-CoA reductase.  This is one of the first known wax biosynthetic enzymes.  We propose to examine the substrate specificities of CER4 and CER4-like proteins and use this information to manipulate cuticular wax composition.  We also plan to determine the sub-cellular location of CER4 to gain insights into the compartmentalization of wax biosynthesis.  In addition, the putative metabolic roles of two other proteins, CER1 and WAX2/CER3, will be investigated.  We will clone additional CER genes using map-based approaches with the aim of identifying novel wax biosynthetic enzymes, regulatory proteins, and proteins involved in wax secretion.  Molecular and biochemical studies of these gene products will be pursued to determine their respective roles in wax biosynthesis.        Our work will make significant contributions towards understanding plant wax biosynthetic pathways and the development of the plant cuticle.  Ultimately, our aim is to generate important information for the genetic engineering of wax accumulation to improve the ability of crop plants to withstand drought, pathogens, and other environmental stresses.

所有陆地植物都覆盖着一层蜡质“皮肤”，称为角质层，它是防止水分流失、紫外线、病原体和昆虫的保护屏障。角质层主要由角质和蜡形式的脂质组成。角质层内蜡嵌入三维角质基质中，而表皮蜡通常以晶体形式覆盖外表面。 我们研究计划的总体目标是了解角质层蜡是如何合成的，然后沉积在植物表面。遗传研究表明，大量蛋白质参与角质层蜡的产生，但只有一小部分已经被确认。我们正在利用蜡-缺陷或'cer'突变体的模式植物拟南芥中，以确定和功能特征的基因产物参与蜡的生物合成和沉积。CER 4，编码一种形成醇的脂肪酰辅酶A还原酶。这是最早已知的蜡生物合成酶之一。我们建议检查CER 4和CER 4样蛋白的底物特异性，并利用这些信息来操纵表皮蜡的组成。我们还计划确定CER 4的亚细胞位置，以深入了解蜡生物合成的区室化。此外，另外两种蛋白质CER 1和WAX 2/CER 3的假定代谢作用将被研究。我们将利用基于图谱的方法克隆另外的CER基因，目的是鉴定新的蜡生物合成酶，调节蛋白，以及与蜡分泌有关的蛋白质。将对这些基因产物进行分子和生物化学研究，以确定它们各自在蜡分泌中的作用生物合成 我们的工作将对理解植物蜡质的生物合成途径和植物角质层的发育做出重要贡献。最终，我们的目标是为蜡质积累的基因工程提供重要信息，以提高作物抵御干旱，病原体和其他环境胁迫的能力。