Phytochrome in the Fern,Adiantum capillus-venerisL.: Spectrophotometric Detection in Vivo and Partial Purification

摘要

Spectrophotometric studies of fern phytochrome were performed using dark-grown leaves ofAdiantum. The absorbance difference spectrum between the red- and far-red-light irradiated sample showed a photoreversible absorbance change in the far-red region, with a maximum located at 728–730 nm. The concentration of phytochrome was highest at the leaf tips and decreased gradually along the leaf axis. As in the case of angiosperm phytochrome, the level of fern phytochrome decreased under continuous white light, and the level increased again when deetiolated tissue was transferred back to the dark. When the fern tissue was exposed to a pulse of red light, the dark reversion of PFRto PRtook place with almost no destruction of PFR. Phytochrome could be extracted from light-grown young leaves of the fern with a slightly alkaline, aqueous buffer that contained 1 M NaCl. The difference spectrum of the partially purified phytochrome from fern was similar to that of partially degraded phytochrome from angio-sperms. A polyclonal antibody raised against phytochrome from etiolated rye seedlings immuno-stained (albeit weakly) a 110-kDa polypeptide after fractionation by SDS-polyacrylamide gel electrophoresis of the preparation of fern phytochrome. The band was very probably fern phytochrome since it emitted zinc-induced fluorescenc