Abstract
Plant nuclear genomes encode many cyanobacterial-like genes. The number of these genes is predicted to be ~3,000 in Arabidopsis, but most of these genes have not been identified. We are attempting mass identification of highly conserved genes among 8 cyanobacteria, Cyanidioschyzon, and Arabidopsis but not conserved among nonphotosynthetic organisms. Consequently, The 56 proteins were selected. We termed these as Chloroplast Proteins of Endosymbiont Origin (CPRENDO). The SALK T-DNA insertion lines for the 56 CPRENDO (CPR) genes were systematically characterized. The cpr27 mutant showed cotyledon-specific albino phenotype. Interestingly, some cells of albino cotyledon contain mature chloroplasts as well as undeveloped plastids, suggesting that CPR27 is critical for plastid development in cotyledons. Although no visible color phenotypes were observed, analysis by the saturation pulse method revealed that CPR27 also affects chloroplast functions in foliage leaves.
