Identification of the gene encoding granule-bound starch synthase I in sweet potato (Ipomoea batatas (L.) Lam.)

Abstract

The cDNA and genomic clones from sweet potato encoding granule-bound starch synthase I (GBSSI) were isolated and characterized. The sequence analysis of the cDNA shows that the sweet potato GBSSI mature protein is comprised of 531 amino acids and that the precursor has a transit peptide of 77 amino acids. A comparison of the cDNA and genomic sequences suggested that the sweet potato GBSSI gene has 14 exons and 13 introns, the first of which is located in the untranslated region. This gene is considered to be a low-copy gene based on genomic Southern analysis.