Abstract
The chloroplast NAD(P)H dehydrogenase (NDH) complex reduces plastoquinones and generate H+ gradient using NAD(P)H in photosystem I cyclic electron flow and chlororespiration. The NDH complex is found in higher plants and cyanobacteria, and a number of NDH-related genes were characterized, while whole machiney of NDH is not identified yet. Last few years, we have succeeded to identify novel genes related to NDH activity, NDH-Dependent cyclic electron Flow (NDF), using a co-expression analysis of Arabidopsis. Among NDF genes, NDF2 had a weak homologue gene, NDF5.
Here we report that NDF5 is related to NDH activity as well as NDF2. Unique presence of NDF2 and NDF5 in higher plants suggests that these genes are acquired by higher plants evolutionally. Functional roles of these proteins in NDH activity are investigated in the comparison with known NDH subunit using Blue Native PAGE analysis.
