Abstract
The massive accumulation of photosynthetic proteins in chloroplasts depends on many nucleus-encoded factors. In order to identify genes involved in the massive accumulation of photosynthetic proteins including RuBisCO, we have isolated the six recessive Arabidopsis EMS mutants that show low RuBisCO amounts. These were named nara (genes necessary for the achievement of RuBisCO accumulation) mutants. Among them, nara5-1 showed a markedly decrease in plastid-encoded photosynthetic proteins including RuBisCO. Map-based cloning revealed that NARA5 (At4g27600) encodes a pfkB-type carbohydrate kinase family protein of unknown function. Analysis of photosynthetic gene expressions during light-induced greening of etiolated seedlings in nara5-1 and T-DNA insertion mutant, nara5-2, indicates that NARA5 is essential for the massive expressions of plastid-encoded photosynthetic genes such as rbcL.
