Abstract:

In this study，a soluble starch branching gene（SBE）was isolated from the leaf of ‘Xiangtangyu’，a species of taro based on RT-PCR and PCR-RACE methods. The full-length of SBE cDNA（GenBank accession number KX013544）was 3 051 bp in nucleotide containing an open reading frame of 2 538 bp which encoding 845 amino acids. Phylogenetic analysis showed that SBE had more than 85% homolog with maize，potato and rice，respectively. SBE protein contained N-terminal end，C-terminal end and alpha amylase catalytic domain. DNA sequence of SBE was cloned by RT-PCR method，and the full length of DNA was 12 362 bp with 20 exons and 19 introns. During corm formation the expression of SBE in leaf of son-taro plants was significantly higher than that of mother-taro plants，leafstalks，roots，mother-taro and so on，the expression was improved in son-taros，and decreased in grade-taros with development of corm. Totally，we believed that the expression of SBE was synchronous with amylopectin synthesis in son-taros and grade-taros.

Key words: Colocasia esculenta, starch branching gene, clone, expression