紫云英AGL18(AGAMOUS-LIKE18)基因克隆及功能鉴定

Cloning and Functional Identification of A GL18(A GA MOUS-LIKE18)Gene in Astragalus sinicus

紫云英(Astragalus sinicus)是重要的绿肥作物,选育花期适当的品种是重要的育种目标。AGL18是关键的开花抑制基因,为了探究紫云英AGL18基因的功能,本研究通过RACE技术成功克隆了紫云英AGL18基因,基因cDNA全长为957 bp,含有1个738 bp的开放阅读框,编码的蛋白质含有245个氨基酸。编码的氨基酸序列与大豆、蒺藜苜蓿、菜豆的同源蛋白相似性均在77%以上,具有较高的保守性。基因表达分析显示,紫云英AGL18基因在各器官中均有表达,表达量由高到低依次为花芽、花、叶、根、叶芽、茎、荚果。通过超表达AGL18基因拟南芥验证了该基因的功能,结果证明,超表达AGL18基因拟南芥株系的抽薹天数比野生型平均迟10.78 d,开花天数比野生型平均迟11.28 d。本研究为调控紫云英花期提供了科学依据。

Astragalus sinicus has been identified as one of the most important green manures,and selecting flowering varieties is an important breeding target of Astragalus sinicus.AGL18,a key flowering suppressor gene,was successfully cloned for exploring the function of AGLI8 gene by RACE technology in Astragalus sinicus.The complete sequence ofAGL18 gene obtained was 957 bp in length,which contained the open reading frame of 738 bp encoding 245 amino acids.Its encoded amino acid sequence was highly homologous,more than 70%with that of Glycine max,Phaseolus vulgaris,Medicago truncatula,which is highly conserved.The RT-qPCR analysis ofAGL18 gene showed that the AGL18 gene was expressed in various organs,and the expression levels were flower buds,flowers,leaves,leaf buds,roots,stems and pods in order from high to low.The function of the gene was verified by overexpression of the AGL18 gene in Arabidopsis thaliana.The results showed that the number of bolting days of Arabidopsis overexpressing AGL18 was 10.78 days later than that of wild type,and the time offlowering was 11.28 days later than that of wild type.It was further verified that the A GL18 gene may regulate its flowering mechanism.The experimental results provide a scientific basis for the further development of flowering in Astragalus sinicus.