Host: The Japanese Society of Plant Physiologists
Pages 0101
Chloroplasts possess their own genome and the protein synthesis system. The molecular mechanisms for chloroplast protein synthesis have not been fully understood in higher plants. To gain new insights into the mechanism of chloroplast protein synthesis, we have isolated nara (genes necessary for the achievement of RuBisCO accumulation) Arabidopsis mutants which had defects in the chloroplast protein synthesis. In nara12, the translation rate of chloroplast-encoded large subunits of RuBisCO was much lower than that of the wild type. Reduced protein levels were found for not only RuBisCO but also several other photosynthetic proteins. In addition, the processing of chloroplast 23S ribosomal RNA (rRNA) was impaired in this mutant, while that of the other chloroplast rRNAs was slightly affected. These results suggest that NARA12 is involved in the chloroplast protein synthesis via the processing of chloroplast 23S rRNA.
