Abstract
RubisCO of higher plants is a hexadecamer of eight large subunits (LSU) and eight small subunits (SSU). RubisCO is quickly and abundantly synthesized in the leaves during greening. Moreover, it is disintegrated in senescence and stress. The details of the mechanism of its biosynthesis and degradation are still unclear. In this study, we analyzed the composition of RubisCO subunits of the extracts of greening radish cotyledons. 2D-PAGE revealed that the insoluble fraction obtained by centrifugation of the leaf extracts contained SSU without LSU. The amount of the insoluble SSU decreased during the progression of greening. We reason that there may be an imbalance in the rates of synthesis of LSU and SSU during greening. This study was partly supported by the Research Association for Biotechnology subsidized by the Ministry of Economy, Trade and Industry of Japan.
