Isolation and characterization of polymorphic cDNAs partially encoding ADP-glucose pyrophosphorylase (AGPase) large subunit from sweet potato

cDNA clones encoding sweet potato AGPase large subunit (iAGPLI) from the cD NA library constructed from the tuberous root were isolated, Two clones wer e characterized and named iAGPLI-a and iAGPLI-b. They were 1,661 bp and 1,2 77 bp in length and contained partial open reading frames of 450 and 306 am ino acids, respectively. Both nucleic acid and amino acid sequence identiti es between iAGPLI-a and iAGPLI-b were 83.8% and 97.3%, respectively. Based on the amino acid sequence analysis, iAGPLI-a and iAGPLI-b share the highes t sequence identity (81%) with potato AGPase large subunit. The iAGPLI-a an d iAGPLI-6 genes were expressed predominantly in the stem and weakly in the tuberous root, and no transcript was expressed in other tissues. The sweet potato genome contains several copies of the iAGPLI gene.