多花水仙花香相关基因的发掘与功能鉴定

Flower fragrance is a composite character that is determined by a complex mixture of low-molecular-mass volatile molecules. Due to the invisibility and the highly variable nature, the characterization of enzymes and genes involved in flower scent production and emission is still in its initial stages. In this project, high-throughput RNA sequencing will be used to obtain genome-wide transcripts of the Yunxiang, Jinzhanyintai, and Yellow narcissus, and the floral ingredients of the three varieties will be determined by gas chromatography-mass spectrometry (GC-MS). We expect to find floral fragrance-related genes on the basis of metabolite profiling analysis and transcriptome analysis. Then, the genes will be cloned in full-length, and their function will be studied using bioinformatic analysis, fluorescent quantitation PCR, and other available techniques. Through this, the key functional genes will be locked. After that, we will clone the promoter of these key floral fragrance-related genes, and the binary vector in which key genes driven by corresponding promoter will be constructed and then transformed into tobacco. This porject is a continuation and extension of our previous work of genetic researches and breeding practices over the past 30 years, and hopefully will better understand the molecular mechanism of floral formation, as well as provide candidate genes for the fragrance-oriented breeding of narcissus.

花香成分复杂，涉及到的合成途径较多，且易受环境条件影响，人们对花香生物合成和调控机制的了解还较粗浅。本项目拟采用高通量转录组测序技术获得'黄花水仙'、'云香水仙'和'金盏银台'的花蕾期、始花期和盛花期的全部转录本信息，同时用气相色谱-质谱联用仪测定3个品种各发育时期花的芳香成分，将转录组学分析与代谢物谱分析相结合，发掘花香形成相关候选基因。克隆候选基因全长，采用生物信息学分析、荧光定量PCR等技术分析候选基因，锁定花香形成关键基因；克隆花香形成关键基因启动子，将有效启动子片段与关键基因构建植物表达载体，转化烟草进行功能验证。本项目是课题组 30 年来从事中国水仙遗传背景及育种研究的延续和拓展，该项目的顺利完成将有助于揭示水仙花香形成的分子机制，为利用基因工程技术进行花香育种提供基因资源，对充实多花水仙基础理论和指导育种实践具有重要意义。

多花水仙是石蒜科水仙属植物，其花枝多，花香浓郁。香气是观赏植物不可缺少的一个重要品质，水仙的花香物质非常复杂，主要包括酯类、萜类、醛类、醇类等。本研究对多花水仙花香成分进行分析并进行了相关基因的克隆和表达分析，不仅可以为花香物质开发利用提供参考，还可为运用转录组技术从分子层面更深入地研究花香形成机理提供取材采样依据。.主要研究结果如下：.1.利用气质联用仪分析了‘云香水仙’不同花期的花香成分，对‘黄花水仙2号’、‘金盏银台’的盛花期花香成分也进行了分析。结果表明：在多花水仙中反式罗勒烯和乙酸苄酯是主要的花香物质，在花香构成中起主要作用。.2.在‘黄花水仙2号’、‘金盏银台’中克隆了WRKY和HDS基因cDNA全长序列并进行了表达分析。