Abstract
In higher plants, the chloroplastic NAD(P)H dehydrogenase (NDH) complex is involved in PSI cyclic electron transport. Eleven genes encoding the subunits of the NDH complex have been discovered in chloroplast genome based on their sequence similarity to the subunit genes of the mitochondrial complex I (NADH dehydrogenase).Recently three novel subunits encoded in nuclear genome have been isolated by the biochemical method. To understand full structure of the chloroplastic NDH complex, we have screened 7 novel candidate ndf (NDH-Dependent cyclic electron Flow) genes essential for NDH activity through co-expression analysis and phylogenetic methods. In this report we show the results of Blue Native-PAGE analysis of NDH complex in Arabidopsis ndf mutants, which lack NDH activity, and C4 plants, which show high expression of NDH genes as compared with C3 plants. From these analyses, we discuss the interaction of the novel ndf subunits and the known NDH subunits.
