PUB - Publikationen an der Universität Bielefeld

The presence of phytochrome or a phytochrome-like photoreceptor in the microscopic unicellular green algae Dunaliella and Chlorella had been suggested by us from results of physiological studies. Spectroscopic and immunological procedures are now introduced to support this suggestion in these and some other green algae. Difference spectra of protein preparations from Dunaliella and Chlorella, obtained by measuring red or far-red light treated samples versus dark controls, show a negative or positive deflection, respectively, at about 670 nm, but no change in the far-red region. The antibody Z-3B1 specific for the chromophore-containing domain of Zea phytochrome but also cross-reacting with phytochrome from ferns, mosses, and macroscopic algae like Ulva was then used for immunological studies. Since a protein of about the same weight - 121 kDa - was recognized by this antibody in extracts of Dunaliella and also of Chlamydomonas, presence of phytochrome in these green algae seems highly probable. For Monoraphidium, Chlorella, and Euglena immunoblot bands appear in the range of 65 to 100 kDa, making the interpretation rather ambiguous.