Spectral properties of system I-deficient mutants of Chlamydomonas reinhardi. Possible occurrence of uphill energy transfer.

Chlamydomonas reinhardi mutants lacking the P-700-chlorophyll alpha-protein complex CPl, lack as well the long wavelength forms of chlorophyll Ca 691 and Ca 704 normally present in the absorption spectrum at -196 degrees C. These mutants do not display the 715 nm peak in the fluorescence emission spectrum at -196 degrees C. Studies of the System II action spectrum of one such mutant show an increase in the optical cross-section of the System II centers around 685 nm. This is interpreted as an energy transfer from pigment System I to pigment System II occurring in the mutant.