Abstract
There are three rice starch branching enzymes (BE): BEI, BEIIa, and BEIIb, each having a different function and expression pattern. The individual function and probable interactions of these genes were analyzed by posttranscriptional silencing thraugh RNAi. Seven gene constructs (one each for the three BE genes, and their combinations- BEI+IIa, BEI+IIb, BEIIa+IIb, BEI+IIa+IIb) were made and their T1 seeds were analyzed.
Silencing of BEI or BEIIa gene alone had no visible effect on seed morphology, while silencing of BEIIb resulted into the production of small seeds with whitish endosperm. Although the combined BEI + BEIIa silencing did not affect the seeds, the three silencing combinations BEI+IIb, BEIIa+IIb, and BEI+BEIIa + BEIIb yielded seeds with shriveled whitish endosperm, indicating that the genes interact synergistically to regulate starch biosynthesis in rice endosperm.
