决定墨兰叶艺（叶色变异）性状的分子调控机制研究

项目名称： 决定墨兰叶艺（叶色变异）性状的分子调控机制研究

项目编号： No.31471915

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 农业科学

项目作者： 朱根发

作者单位： 广东省农业科学院环境园艺研究所

项目金额： 83万元

中文摘要： 叶色变异性状是国兰园艺观赏和经济价值的重要指标，也是国兰品种选育的主要发展方向之一，而长期以来，对调控国兰叶色变异性状的分子机制还知之甚少。我们以变异发生率最高的墨兰'达摩'品种为研究对象，首次完成其转录组测序及变异叶片基因表达谱差异分析。发现变异叶片体内叶绿素降解大于合成， 且细胞降解代谢途径相关基因和WRKY转录因子被显著诱导表达。推测叶绿素过量降解是造成叶色变异的主要原因之一，且WRKY转录因子可能在其中发挥重要调控作用。本项目将深入研究墨兰叶绿素代谢通路，阐明叶绿素分解代谢途径关键酶基因功能，并在转录组水平找出影响分解代谢途径的关键调控因子，重点研究WRKY转录因子及其下游应答基因的调控机制，建立墨兰叶色变异性状的分子调控模型，为墨兰园艺性状改良及分子育种提供切实可行的理论指导。

中文关键词： 墨兰；叶色变异；叶绿素代谢；转录组测序；调控机制

英文摘要： Leaf variation is an very important character for the horticultural and economic value of Chinese Cymbidium. It also become one of the main development trend of Cymbidium breeding. However, the mechanism of leaf variation is still poorly understood. In our previous work, we sequenced the transcriptome of Cymbidium 'Dharma', which is a well-known orchid species in Cymbidium sinense with highly variable leaf arts, and analyzed the difference of gene expression profile between the normal and the variated leaves using DGE(Digital gene expression). Our results showed that the chlorophyll degradation is greater than the synthesis in mutation leaves, and the genes involved in cellular metabolic pathway are highly expressed as well as the WRKY transcription factors. We therefor speculated that the excess degradation of chlorophyll mainly caused leave color variation,and the WRKY transcription factors may be involved in regulating this process.On this basis, this project will focus on chlorophyll metabolic pathway, clarify the functions of the key enzyme genes for chlorophyll degradation firstly, and then screen the regulatory factors which affect chlorophyll content through transcriptome profiling, (especially focus on WRKY transcription factor and the downstream responsive genes ), in order to initially reveal the molecular basis of the regulation of leaf color variation. Our study will provide valuable data and practical guidance for improving the horticultural traits and molecular breeding in Cymbidium.

英文关键词： Cymbidium sinense;Leaf variation;Chlorophyll metabolism;Transcriptome sequencing;Molecular mechanism