洋葱成花素基因AcFT的克隆与表达分析

Molecular Cloning and Expression Analysis of AcFT Florigen Gene in Allium cepa

以春化后但尚未抽薹的洋葱品系‘1007’的叶片为试材,采用RT-PCR结合RACE的方法克隆得到了洋葱成花素基因的cDNA全长序列,将其命名为AcFT(GenBank登录号为KF913629)。该基因cDNA全长791 bp,开放读码框为534 bp,推测其编码的蛋白由177个氨基酸残基组成,等电点为7.89,分子量为19.8 kD。将AcFT与大葱、鸢尾等植物的成花素氨基酸序列进行同源性比对,结果显示洋葱与其他植物的氨基酸序列同源性均在65%以上,其中洋葱与大葱的成花素氨基酸的同源性高达98.31%。实时荧光定量RT-PCR分析结果表明,洋葱AcFT基因在抽薹前后的根、叶鞘、叶片、假茎和花序等不同部位均有表达,尤以春化后抽薹前的叶片中表达量最高。

The florigen gene which designated as AcFT isolated from the leaf of Allium cepa line,‘1007'from vernalization period to bolting period(GenBank accession No.KF913629).The full-length cDNA of florigen gene in A.cepa was obtained by RT-PCR and Rapid Amplification of cDNA Ends.The cDNA sequence of AcFT was 791 bp long and the open reading frame was 534 bp long which could encode a putative protein of 177 amino acids with a molecular weight of 19.8 kD and a theoretical pI of 7.89.Compared and analyzed the amino acid sequence of florigen gene with Allium fistulosum,Iris fulva and so on,the A.cepa shared over 65% nucleotide sequence similarity with others and the similarity of amino acids with the florigen gene in A.fistulosum is 98.31%.Fluorescence quantitative RT-PCR system followed was established to examine the expression of AcFT.As a result,the AcFT gene from A.cepa detected during th e different tissues that was root leaf sheath,leaf,stem and inflorescence from bolting to vernalization,and it was highly expressed in leaves before bolting after vernalization.