Translational Regulation of Light-Induced Ribulose 1,5-Bisphosphate Carboxylase Gene Expression in Amaranth

Abstract

The regulation of the genes encoding the large and small subunits of ribulose 1,5-bisphosphate carboxylase was examined in amaranth cotyledons in response to changes in illumination. When drk-grown cotyledons were transferred into light, synthesis of the large- and small-subunit polypeptides was initiated very rapidly, before any increase in the levels of their corresponding mRNAs. Similarly, when light-grown cotyledons were transferred to total darkness, synthesis of the large- and small-subunit proteins was rapidly depressed without changes in mRNA levels for either subunit. In vitro translation or in