建兰AGL6基因的表达及功能分析

Expression and Function Analysis of AGL6 Homologous Genes in Cymbidium ensifolium

采用文库稀释池法从建兰花器官全长均一化cDNA文库中筛选出1个AGL6类MADS-box基因CeAGL6,对其进行了信息学分析,并通过表达模式、互作蛋白和烟草的遗传转化研究其功能。研究结果发现,CeAGL6含有MADS结构域和K结构域,并具有AGL6类蛋白的典型基序。CeAGL6在建兰萼片中高水平表达,其次是花梗,在花瓣、唇瓣和合蕊柱中表达水平较低,不在叶片和根中表达。转CeAGL6烟草花期略微提前,出现四瓣花、六瓣花、雄蕊瓣化和多种不规则的五瓣花等表型。CeAGL6与CeAP1、CePI1、CeAG1和CeSEP3能互作,但自身不能形成同源二聚体。试验结果表明Ce AGL6参与了建兰成花诱导和花器官发育。

CeAGL6,a gene belongs to AGL6 class of the MADS-box gene family,was isolated from a normalized full-length cDNA library of Cymbidium ensifolium based on pooling strategy combined with PCR-based screening method.After bioinformatics analysis of CeAGL6,expression patterns,interacting protein and tobacco genetic transformation were performed to identify its functions in the flower development of Cymbidium ensifolium.Sequence analysis revealed the highly conserved MADS domain,K domain,and a typical motif of AGL6 class of MADS-box gene family in CeAGL6.The highest expression level of CeAGL6 was found in sepal,followed by pedicels,low level in petal,lip,and column,and expression in leaf and root was not detected.Overexpression of CeAGL6 caused an advanced flowering and novel phenotypes of four-petal flower,six-petal flower,petaloid stamens and a variety of irregular five-petal flower in transgenic tobacco.Yeast two-hybrid analysis indicated there were interactions between CeAGL6 and CeAP1,CePI1,CeAG1 or CeSEP3,but the homodimers cannot form by itself.The results showed that CeAGL6 was involved in promoting flowering and flower organ development of Cymbidium ensifolium.