不同温度对郁金香花芽分化的影响及相关基因表达分析

Analysis of Floral Bud Differentiation and Related Genes Expression Under Different Temperatures in Tulipa gesneriana

以郁金香‘World’sFavourite’品种作为试验材料,比较不同温度条件下郁金香花芽分化和花器官形成过程以及栽培后植株开花情况。结果表明,温度对郁金香花芽分化及完整花芽结构的形成具有显著影响,22℃条件下花芽分化速度最快,花器官结构完整,28℃条件下花芽分化的种球可正常开花且生长速度快,而5℃条件下则不能形成完整的花器官结构。利用荧光定量PCR对花发育和开花时间相关基因表达趋势进行分析,结果表明不同温度条件下分化的花芽中ABC类基因及开花调控基因表达量具有显著差异。进一步对A类基因TgSQA进行克隆和功能探究,结果表明该基因编码246个氨基酸,具有典型的MADS-box和K-box结构域,超表达转基因拟南芥植株相较于野生型呈现出早开花表型,表明TgSQA具有促进开花功能。

In this study,the cultivar‘World's Favourite'was used to compare the processes of floral bud differentiation and floral organ formation under different temperature conditions,as well as a comparison of plant growth and flowering after bulbs planting.The results showed that temperature had a significant effect on the floral buds differentiation and formation of complete flower bud structure.22℃is the most suitable temperature for floral bud differentiation under which the differentiation speed is the fastest and the floral bud structure is intact.Bulbs under 28℃could form normal floral bud and displayed a faster growth,while the complete floral organ structure failed to be formed under 5℃condition.The expression patterns of genes related to flower development and flowering time regulations were further analyzed by qRT-PCR.The results showed that ABC family genes and flowering time related genes were significantly different in floral buds differentiated under different temperatures.Further cloning and functional exploration of the class A gene TgSQA demonstrated that it encoded 246 amino acids with a typical MADS-box and K-box domain.TgSQA over-expressed transgenic Arabidopsis thaliana obtained an early flowering phenotype compared with the wild type,indicating that TgSQA was a positive regulator during flowering time regulation.