Characterization of cDNAs encoding two isoforms of granule-bound starch synthase which show differential expression in developing storage organs of pea and potato

Plant J. 1992 Mar;2(2):193-202.


We have isolated cDNA clones to two isoforms of granule-bound starch synthase (GBSS) from pea embryos and potato tubers. The sequences of both isoforms are related to that of glycogen synthase from E. coli and one, GBSSI, is very similar to the waxy protein of maize and other species. In pea, GBSSII carries a novel 203-amino-acid domain at its N-terminus. Genes encoding both proteins are expressed during pea embryo development, but GBSSII is most highly expressed earlier in development than GBSSI. Similarly, GBSSI and GBSSII are differentially expressed in developing potato tubers. Expression of both isoforms is much lower in other organs of pea than in embryos. GBSSII is expressed in every organ tested while GBSSI is not expressed in roots, stipules or flowers. The possible consequences of this differential use of GBSS isoforms are discussed.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Cloning, Molecular
  • Fabaceae / enzymology*
  • Fabaceae / genetics
  • Genes, Plant / genetics
  • Isoenzymes / genetics*
  • Molecular Sequence Data
  • Multigene Family / genetics
  • Plant Proteins / genetics*
  • Plant Proteins / metabolism
  • Plants, Medicinal*
  • Polymerase Chain Reaction
  • RNA, Messenger / genetics
  • RNA, Messenger / isolation & purification
  • Seeds / enzymology
  • Seeds / growth & development
  • Sequence Analysis
  • Sequence Homology, Amino Acid
  • Solanum tuberosum / enzymology*
  • Solanum tuberosum / genetics
  • Starch Synthase / genetics*
  • Starch Synthase / metabolism
  • Tissue Distribution


  • Isoenzymes
  • Plant Proteins
  • RNA, Messenger
  • waxy protein, plant
  • Starch Synthase