东方山羊豆赤霉素受体基因GoGID对紫花苜蓿株高的调控作用分析

Alfalfa (Medicago sativa L.) is a widely planted perennial forage legume grown in the world. Long breeding cycles limit genetic improvement of alfalfa, particularly for complex traits such as biomass yield. Plant height is one of the most important factors that affect forage biomass, studying and exploring the genes associated with plant height and using them to breed new varieties is one of the effective ways to improve the alfalfa yield. Based on the previous research work, a gibberellin receptor gene, GoGID, was cloned from Galega orientalis, which was shown strongly increased plant height by overexpressing in tobacco, Arabidopsis and alfalfa. This study intends to reveal the molecular mechanism with higher biomass in alfalfa by compared with the different related genes between transgenic plants and control plants by using of transcriptome sequencing technology. Moreover, interaction proteins of GoGID will also be screened using yeast two-hybrid system. These results will provide important theoretical significance and application value in revealing the mechanism of GoGID involved in higher biomass production in alfalfa and may applicable to breeding programs to generate new germplasm in alfalfa or other forages.

紫花苜蓿（Medicago sativa L.）是世界上种植最广泛的多年生豆科（Leguminous）牧草。育种周期长，限制了紫花苜蓿的遗传改良，尤其是生物量等复杂性状。株高是影响牧草产量最重要的因素之一，研究、发掘和利用株高相关基因是培育苜蓿新品种的有效途径之一。项目组在前期的研究工作中，克隆了一个与调控株高相关的基因GoGID（东方山羊豆赤霉素受体基因），并通过过量表达该基因的方式证实其可以增加烟草、拟南芥和苜蓿的株高。本项目拟利用转录组测序技术对转基因苜蓿植株与对照植株的表达差异基因进行鉴定，比较信号传导通路相关基因的表达变化；结合酵母双杂技术筛选GoGID的互作蛋白，明晰其调控作用网络，从而解析GoGID对苜蓿株高的调控作用。为揭示赤霉素受体基因对苜蓿生物量的影响以及高产紫花苜蓿新种质的培育提供分子依据。

紫花苜蓿是我国最重要的豆科牧草。经过了3年的研究，本项目取得了以下成果：（1）在温室环境中，转基因GoGID紫花苜蓿与对照相比，叶片变大、株高、生物量增加；（2）在大田条件下转基因与对照无明显差异；（3）GoGID增强了转基因植物的赤霉素信号途径。发表SCI文章1篇。该项目分析了东方山羊豆赤霉素受体基因GoGID对紫花苜蓿株高、生物量的调控作用，为今后候选基因挖掘和利用提供了借鉴。