IC4R  Rice Literature Database

Molecular cloning and expression analysis of three genes encoding starch synthase II in rice.

Three starch synthase (SS) genes, OsSSII-1, m' data-tid='22422' href='#term-22422'>OsSSII-2 and OsSSII-3, were identified in rice (Oryza sativa L.) and localized to chromosomes 10, 2 and 6, respectively. The three OsSSII full-length cDNAs were cloned, and the predicted amino acid sequences were found to share 52-73% similarity with other members of the plant SSII family. The SS activity of each OsSSII was confirmed by expression and enzyme activity assay in Esch424'>erim' data-tid='22427' href='#term-22427'>-tid='22426' href='#term-22426'>chia coli. Expression profile analysis revealed that OsSSII-1 was expressed in endosperms, leaves and roots; OsSSII-2 was mainly expressed in leaves, while OsSSII-3 was mainly expressed in endosperms. Similar to the OsSSI proteins, the OsSSII-2 and OsSSII-3 proteins were found in the soluble as well as the starch-granule-bound fractions in rice. The roles of the OsSSII proteins in starch biosynthesis in rice and the evolutionary relationships of the genes encoding monocotyledonous and dicotyledonous class-II SS enzymes are discussed.