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

Abstract：Two full-length cDNA sequences of homologous FT genes were cloned based on homologous A PI 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 LcFF1 and LcFT2 proteins all have 4 oL helices and 10 J3 sheets. A comparison of the nucleotide sequences of homolo- gous FF 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.