Six putative photosystem I mutants in five different nuclear genes of barley have been characterized with respect to their photosynthetic electron transport capabilities, P700, cytochromes, chlorophyll-proteins and other thylakoid polypeptides. Three of these mutants (viridis-n 34, -zb 63, and -h 15) have normal photosystem II activities but are wholly or partly deficient in photosystem I electron transport, P700, chlorophyll, a-protein 1 and its apoprotein. These three mutants also lack low molecular weight polypeptides which are believed to be integral photosystem I iron-sulfur centres. Of the remaining mutants, xantha-q 75 and -q 76, which are allelic, are mainly depleted in photosystem II and the other (viridis-q 42) had aout 75% of the wild-type activity in both photosystems. The data are discussed in relation to the fluorescence induction kinetics and low temperature fluorescence emission spectra of the mutants.
- difference spectra
- Fluorescence induction kinetics
- SDS-polyacrylamide gel electrophoresis