Abstract
In a virescent mutant of rice, leaves in seedling is initially yellow with less chlorophyll, and then gradually becomes more greenish as the mutant grows. The mutable virescent plant, pyl-v (pale yellow leaves variegated) showed yellow leaves with green sectors, and the variegation was caused by recurrent somatic mutation from the recessive pyl-v allele to the green Pyl-r (Pyl-revertant) allele. We showed that the pyl-v allele is caused by the disruption of a nuclear-coded chloroplast protease gene, OsClpP5 due to an insertion of a novel DNA transposon, nDart1. We showed that OsClpP5 can be localized in chloroplasts and that the defects in grana stacks of chloroplasts of yellow leaves in seedlings do not recover even after the leaves become green. Phenotypic features in pyl-v mutant with regard to the expression of OsClpP5 gene itself and environmental factors affecting the OsClpP5 expression will be discussed.
