EFFECT OF CADMIUM ON ORGANIZATION AND PHOTOREDUCTION OF PROTOCHLOROPHYLLIDE IN DARK-GROWN LEAVES AND ETIOPLAST INNER MEMBRANE PREPARATIONS OF WHEAT

The cadmium treatment of dark-grown leaves and isolated etioplast inne r membranes of wheat resulted in a decrease of the amount of the 657 n m emitting (77 K fluorescence) protochlorophyllide (PChlide) form, a s imultaneous increase of the 633 mm form and the appearance of a 641.5 nm emitting form. This effect did not occur if excess NADPH was added to the isolated membranes: these samples showed spectral properties id entical to those of non-treated (control) samples. Inhibition of the P Chlide phototransformation was observed in the cadmium-treated leaves and membranes, the irradiation resulted in the appearance of a small a mount of chlorophyllide (Chlide) with characteristic emission band at 678 nm. If excess NADPH was added, the inhibition did not occur and fl ash irradiation resulted in formation of the 694 nm Chlide form simila rly as in control plants.