title: Reversible redistribution of phytochrome within the cell upon conversion to its physiologically active form.
abstract: The intracellular localization of phytochrome was seen in dark-grown oat (Avena sativa L., cv. Garry) and rice (Oryza sativa L., cv. unknown) shoots after various light treatments using an indirect peroxidase-antiperoxidase antibody labeling method. Phytochrome is generally distributed throughout the cytoplasm in cells of tissue that had not been exposed to light prior to fixation. Within, at most, 8 min after the onset of saturating red irradiation, phytochrome, now present in the far-red-absorbing form, becomes associated with discrete regions of the cell. These regions do not appear to be nuclei, plastids, or mitochondria. After phototransformation back to the red-absorbing form originally present, phytochrome slowly resumes its general distribution. It is possible that this discrete localization of the far-red-absorbing form of phytochrome represents a physiologically significant binding with a receptor site in the cell.
mesh_terms: D003593:Cytoplasm / Q000032:analysis; D007158:Immunologic Techniques; D008027:Light; D010544:Peroxidases; D010777:Photochemistry; D010860:Pigments, Biological / Q000032:analysis*; D010940:Plant Proteins / Q000032:analysis*; D010944:Plants / Q000032:analysis* / Q000648:ultrastructure
chemical_list: D010860:Pigments, Biological; D010940:Plant Proteins; D010544:Peroxidases