荔枝FLOWERING LOCUST(FT)同源基因cDNA全长克隆及其表达

应用RT-PCR方法在首次克隆获得荔枝AP1同源基因cDNA全长基础上,又得到2个荔枝FT同源基因cDNA全长,分别命名为LcFT1和LcFT2(基因登录号分别为:JN214350、JN214351)。LcFT1基因开放阅读框522 bp,编码174个氨基酸,推测蛋白质分子质量为19.65 ku,等电点为8.68。LcFT2基因开放阅读框522 bp,编码174个氨基酸,推测蛋白质分子质量为19.56 ku,等电点为7.34。蛋白质二级结构预测表明,LcFT1和LcFT2蛋白都具有4个α螺旋,10个β折叠区。同源分析表明,LcFT1和LcFT2基因在不同植物中的一致性为72%～82%。半定量RT-PCR分析表明,三月红荔枝花芽分化期LcFT1和LcFT2基因只在叶中表达,并且在成熟叶中表达量最多。研究将有助于进一步了解荔枝开花的分子机理及其成花的生物学发育过程。

Cloning and expression analysis of the FLOWERING LOCUS T(FT) homologous gene cDNA from Litchi chinensis

Two full-length cDNA sequences of homologous FT genes were cloned based on homologous AP1 gene we had firstly cloned by employing RT-PCR from Litchi chinensis,which were named as LcFT1 and LcFT2(GenBank accession No.JN214350,JN214351).The open reading frame of LcFT1 gene is 522 bp in length,encoding a protein of 174 amino acids,with an estimated molecular weight and an isoelectric point of 19.65 ku and 8.68 respectively.The open reading frame of LcFT2 gene is 522 bp in length,encoding a protein of 174 amino acids,with an estimated molecular weight and an isoelectric point of 19.56 ku and 7.34 respectively.Prediction of the secondary structure of the protein showed that LcFT1 and LcFT2 proteins all have 4 α helices and 10 β sheets.A comparison of the nucleotide sequences of homologous FT genes from different species indicated that LcFT1,LcFT2 genes have a range of 72% to 82% identity in nucleotide sequence with homologues of other plants.Expression analysis by RT-PCR indicted that LcFT1 and LcFT2 genes expressed only in leaf during flower bud differentiation period of Sanyuehong Litchi chinensis but expressed much in mature leaf.The research is beneficial to the further understanding of the molecular mechanism of Litch flowering and biological developmental stages of flowering.