关键词: 荔枝, APETALA1（AP1）基因, 序列分析, 表达模式

Abstract: A full-length cDNA sequence of homologous AP1 gene was cloned by employing RT-PCR from Litchi chinensis，which was named as LcAP1（GenBank accession No. JN214349）. The LcAP1 gene open reading frame（ORF）is 738 bp in length，encoding a protein of 245 amino acids，with an estimated molecular weight and an isoelectric point of 28.39 kD and 9.69 respectively. The bioinformatics characterization indicated that the protein encoded by LcAP1 gene has a MADS-box domain（1st–61st），a K-box domain（89th–179th）. Prediction of the secondary structure of the protein showed that LcAP1 protein has 3 α-helices，2 β-strands and 8 β-turns. A comparison of the nucleotide sequences of homologous AP1 genes from different species indicated that LcAP1 gene has a range of 72% to 82% identity in nucleotide sequence with homologues of other plants. Expression analysis by RT-PCR indicted that the LcAP1 gene expressed in mature leaf，young leaf，mature stem，young stem，flower bud and peduncle during‘Sanyuehong’litchi flower bud differentiation period，but expressed more in flower bud.

Key words: Litchi chinensis, APETALA1（AP1）gene, sequence analysis, expression pattern