In vitro studies of enzymatic properties of starch synthases and interactions between starch synthase I and starch branching enzymes from rice.

Highlights: [•] Rice starch synthase (SS) isozymes show poor activities toward linear dextrin. [•] SSI specifically elongates the DP6 and 7 chains to form mainly the DP8 chain. [•] SSI and BE specifically interact by activating the mutual capacities each other. [•] The role of BE is not merely to supply SSI with increased primers. [•] The addition of citrate is absolutely required for the SSI–BE interaction. [Copyright &y& Elsevier]