Abstract
A C4 plant maize possesses plastidic 2-oxoglutarate/malate transporter (OMT) and general dicarboxylate transporter (DCT) of which gene expression is photosynthetic cell-specific, although genes for OMT and DCT in C3 plant, Arabidopsis, show constitutive expression patterns. Thus, it is expected that maize OMT and DCT genes have acquired cell-specific expression mechanisms during their evolution from ancestral C3 genes and both of the maize transporters are functionally differentiated for C4 photosynthesis. In this study, we investigated expression profiles and transport properties of OMT and DCTs from rice which is a C3 plant in Gramineae and evolutionally related to maize. We identified one OMT gene (OsOMT1) and two DCT genes (OsDCT1, OsDCT2) from rice. Although the transcripts for OsOMT1 and OsDCT2 were evenly accumulated in rice tissues, that of OsDCT1 were detected only in shoot. We are now studying intercellular distribution of transcripts and transport properties of the rice OMT and DCTs.
