Abstract
About 3500 proteins have been identified in chloroplast. Among them, only 100 plastid proteins are encoded on the plastid genome. Remaining plastid proteins are encoded by the nuclear genome, synthesized as precursors in the cytosol, and then transported to the proper regions for their functions within chloroplasts.
To study function of nuclear genes involved in chloroplast development and photosynthesis, we have started to analyze their functions using Ds-tagged lines. We took two approaches as follows.
(1) To determine essential nuclear-encoded genes for chloroplast development, we have screened 9425 Ds-tagged lines to isolate 38 mutants with albino or pale green (apg) phenotypes. Identified APG genes have sequence homology with housekeeping proteins involved in photosynthesis, translation, transcription, translocation and so on.
(2) To screen mutants with wild-type phenotype but defective in photosystem, we isolated a Ds-tagged mutant showing different fluorescence kinetics from that of wild type using chlorophyll fluorescence monitoring system.
