乙酰辅酶A羧化酶ACC1参与拟南芥蜡质合成响应盐胁迫的功能解析

拟南芥蜡质主要由C30以上超长链脂肪酸（VLCFA）及其衍生物组成，可通过抑制水分非气孔性散失提高植物对盐和干旱胁迫的抵御能力。目前干旱诱导蜡质合成的分子机制取得了重要进展，然而特异参与盐胁迫诱导蜡质合成的基因功能研究未见报道。本项目前期筛选获得特异响应盐胁迫表达的基因ACC1，编码乙酰CoA羧化酶，其突变体对盐胁迫敏感且蜡质中C30以上组分特异缺失。不仅如此，ACC1还与C30以上蜡质合成关键因子CER2-LIKEs存在互作，由此推断ACC1与CER2-LIKEs协同参与蜡质合成响应盐胁迫。在此基础上，本项目拟通过突变体和过表达株系探究ACC1的生理功能，利用分子、细胞和生化技术揭示ACC1与CER2-LIKEs的互作机制及其在蜡质合成中的功能和遗传作用位点，最终阐明ACC1参与蜡质合成响应盐胁迫的分子机制。研究结果将进一步完善蜡质合成调控网络，并为基于蜡质的植物抗盐遗传改良提供新思路。

Arabidopsis cuticular wax is mainly composed of very long chain fatty acids (VLCFA) and their derivatives, whose carbon chain length is longer than 30. Cuticular wax can improve plant resistance to salt and drought stresses by inhibiting non-stomatal water loss. Important progress has been made in research of drought-induced wax synthesis. However, functional characterization of genes specifically associated with salt-induced wax synthesis has not been reported. Previous research of this project revealed ACC1, encoding an acetyl CoA carboxylase 1, specifically expressed in response to salt stress. Furthermore, acc1 mutant was sensitive to salt stress and showed deficiency of wax compounds with carbon chain length longer than 30. In addition, ACC1 interacted with CER2-LIKEs, which are key enzymes in synthesis of wax compounds with carbon chain length longer than 30. This suggested that ACC1 and CER2-LIKEs synergistically participated in wax synthesis in response to salt stress. Based on this, this project proposes to analyze the corresponding mutant and overexpression lines of ACC1 in order to resolve its physiological functions. The interaction mechanism between ACC1 and CER2-LIKEs and genetic relationship of ACC1 and CER2-LIKEs in wax synthesis will be revealed by using molecular, cellular and biochemical techniques. The molecular mechanism of ACC1 in wax synthesis responding to salt stress will be finally clarified. The expected results of this project will improve the regulatory network of wax synthesis and provide new ideas for wax-based genetic improvement of salt resistance of plant.