草莓FaRGA1基因沉默改变开花和匍匐茎抽生特性

FaRGA1 Gene Silencing Changes the Characteristics of Flowering and Runner Producing in Strawberry

RGA是赤霉素信号途径中抑制赤霉素介导反应的核心成分DELLA蛋白的一种,在植物生长发育中扮演重要角色。本研究中预测了栽培草莓FaRGA1的理化特征及二级结构,分析了FaRGA1蛋白保守结构域。系统进化树分析表明FaRGA1蛋白与森林草莓FveRGA1蛋白同源性较高,两者互为直系同源基因。构建了草莓RGA1基因的RNAi载体,以栽培草莓品种‘晶玉’为试材,通过农杆菌介导的遗传转化获得FaRGA1基因被沉默的转基因株系3个。与非转基因对照植株相比,3个FaRGA1沉默株系均表现出连续2年不开花且持续抽生匍匐茎的特性,且短缩茎明显伸长并发生木质化。本研究中发现FaRGA1基因在栽培草莓中对匍匐茎形成具有抑制作用并促进开花,这为今后基于FaRGA1的草莓分子育种奠定了基础。

RGA is one of the DELLA protein that is the core component of inhibition of gibberellin-mediated response in the gibberellin signaling pathway,and plays an important role in plant growth and development. In this study,the physicochemical characteristics and secondary structure of FaRGA1 in cultivated strawberry(Fragaria × ananassa)were predicted and the conserved domain of FaRGA1 protein was analyzed. Phylogenetic tree analysis shows that FaRGA1 has high homology with FveRGA1 in woodland strawberry(F. vesca),and the two are orthologous genes. The RNAi vector of strawberry RGA1 gene was constructed,and 3 transgenic lines with FaRGA1 silencing were obtained from strawberry cultivar ‘ Jingyu ’ by Agrobacterium-mediated genetic transformation. Compared with non-transgenic control plants,all three FaRGA1 silencing lines showed the characteristics of without flowers and continuously producing runners during two years,and the shortened crowns were significantly elongated and lignified. This study found that FaRGA1 gene has an inhibitory effect on tunner formation and promotes flowering in cultivated strawberries,which lays the foundation for molecular breeding of strawberry based on FaRGA1 gene in the future.