兰属花卉CYC-like TCP基因克隆及其在花型调控中的功能研究

CYCLOIDEA-like genes belong to the TCP family of transcriptional regulators and have been shown to control flower monosymmetry in higher plant. CYC-like genes have been found in various plant species, and new roles in plant development have been elucidated. The orchids family involved varied types and the majority of orchids belong to the bilateral symmetry. In order to analyse the characteristics of CYC-like genes in orchid family, the CYC-like gene will be isolated from the species of genus Cymbidium by transcriptome analysis and RT-PCR and RACE technique to identify its spatiotemporal expression patterns. Then constructing the gene vector and Agribacterium-mediated transformation will be conducted to obtain the transgenetic Phalaenopsis plants and analyse the CYC-like gene function in orchid flower symmetry. These results will promote the understanding of the evolution of CYC-like genes in monocots and improve the orchid genetic transformation to gain the new germplastms of orchids.

CYC-like基因是调控植物花型性状的重要基因，属于TCP基因家族，研究表明CYC-like基因均能调控花瓣形状变化进而改变花型。在多种植物中克隆到CYC-like基因表明该基因在植物中具高度保守性，因此，CYC-like基因是改变植物花型性状的理想基因之一。兰科花卉种类丰富，花型奇特，虽属单子叶植物，但无论从花型、蕊柱进化还是突变体表型上均具有CYC-like基因参与调控的证据。本研究拟采用兰科兰属花卉为材料，根据CYC-like保守序列，结合转录组测序分析及RACE技术在兰属花卉中克隆CYC-like TCP基因，并构建载体分析其时空表达特征，同时通过农杆菌转化蝴蝶兰等以获得转基因植株，温室栽培至开花，分析CYC-like基因在花型形成和生长发育中的作用，获得过量表达CYC-like基因或受其RNA干扰的转化株系，明确其调控花型的方式及进化特征，为利用该基因进行分子设计育种提供基础。

CYC-like基因是调控植物花型性状的重要基因，属于TCP基因家族，研究表明CYC-like基因在双子叶植物中均能调控花瓣形状变化进而改变花型。兰科花卉种类丰富，花型奇特，虽属单子叶植物，但无论从花型、蕊柱进化还是突变体表型上均具有CYC-like基因参与调控的证据。为探明CYC-like基因在兰科植物花型调控中的功能，本研究以兰科兰属花卉蕙兰为材料，根据CYC-like保守序列，结合转录组测序分析及同源克隆技术在兰属花卉中克隆到4个CYC-like TCP基因，在蝴蝶兰中克隆到3个CYC-like 基因，并构建载体分析其时空表达特征，通过农杆菌转化夏堇和蝴蝶兰等获得了转基因植株，结果表明CYC-like基因对夏堇花型形成和分枝特征均具有较大影响；通过蝴蝶兰突变体和野生型花器官发育过程中CYC-like基因的表达分析也表明，CYC在蝴蝶兰中参与特化花瓣发育，并影响其花序分枝特征。研究结果为深入探讨CYC基因在兰科花卉中的调控功能提供了基础，也为利用该基因进行分子设计育种提供理论依据。