CHLOROPLAST STRUCTURAL CHANGES INDUCED BY WHITE LIGHT IN THE MARINE DIATOM STEPHANOPYXIS TURRIS1,2

The intensity of white tight used for growing Stephanopyxis Turris (Grev.) Ralfs affects the structure of the chloroplasts. In particular, the conformation of the thylakoids, within the bands is altered by increasing the intensity. At low light (100 μW.cm^-2, 12:12 LD cycles) the thylakoids are generally parallel, whereas at 500 μW.cm^-2 the thylakoids tend to be twisted and out of plane. The possible significance of these conformational changes is discussed.