Abstract
Higher plants chloroplasts contain at least two RNA polymerases; one is plastid-encoded eubacteria-type RNA polymerase (PEP) and other is nuclear-encoded phage-type RNA polymerase (NEP), which is similar to RNA polymerase of bacteriophage T7. It is proposed that the two RNA polymerases transcribe distinct groups of genes, namely, PEP transcribes photosynthetic genes and NEP transcribes housekeeping genes.
In this study, we tried to down-regulate AtRpoT;3 (corresponding to NEP in Arabidopsis) gene expression using RNA interference (RNAi) technique. As a result, we obtained some RNAi mutant lines with lower AtRpoT;3 expression. The RNAi mutants showed cotyledon-specific albino phenotype, and the most chloroplast transcripts of the mutants were hardly accumulated. We currently are analyzing the expression of chloroplast genes in detail.
