A study of phytochrome‐membrane association using an enzymelinked immunosorbent assay and Western blotting

Enzyme‐linked immunosorbent assay (ELISA) and Western blotting have been used to study the association between phytochrome and membranes in dark‐grown tissue of Avena sativa L. cv. Saladin. Enhanced phytochrome pelletability can be demonstrated by ELISA after red irradiation in vivo and extraction in buffer containing Mg2+, but not with red irradiation of Mg2+ alone. This enhanced association may, however, be restricted to specific membranes. The results obtained with ELISA are confirmed by Western blotting techniques. Membrane‐associated and soluble phytochrome give different immunological responses and it is suggested that immunologically distinct populations of phytochrome may exist in dark‐grown tissue.