Light-induced transformation of amyloplasts into chloroplasts in potato tubers.

The transformation of amyloplast into chloroplasts in potato (Solanum tuberosum L.) tuber tissue can be induced by light. Excised potato tuber discs illuminated with white light of 3000 lux began to synthesize chlorophyll after a lag period of 1 day, and continued to synthesize chlorophyll for 3 weeks. In this paper we present evidence, based on ultracentrifugal sedimentation and immunoprecipitation, that the light-mediated synthesis of Ribulose-1,5-bisphosphate carboxylase began 1 day after illumination with white light. When illuminated the chloroplasts isolated from light-grown potato tuber tissue incorporated [(35)S]methionine into polypeptides, one of which has been identified as the large subunit of Ribulose-1,5-bisphosphate carboxylase. These chloroplasts are functional as determined by O(2) evolution in the Hill reaction.