Electron transport activities of Arabidopsis thaliana mutants with impaired chloroplastic NAD(P)H dehydrogenase.

The activities of electron transport are compared between wild-type Arabidopsis and two Arabidopsis mutants deficient for the chloroplastic NAD(P)H dehydrogenase (NDH) which catalyzes cyclic electron transport around photosystem I. The quantum yield of photosystem II and the degree of non-photochemical quenching of chlorophyll fluorescence were of similar levels in the two NDH-deficient mutants and the wild type under non-stressed standard growth conditions. Stromal over-reduction was induced in Arabidopsis NDH mutants with high light treatment, as is the case in tobacco NDH mutants. However, unlike tobacco mutants, photoinhibition was not observed in the Arabidopsis NDH mutants.