Photodynamic activity of cercosporin on plant tissues

Abstract
Cercosporin, excited by incandescent light in the presence of oxygen, induced a loss of ions from the plant tissues tested. Silymarin, BHA (2(3)‐tert‐butyl‐4‐hydroxyanisole) and EDTA were effective in lowering the activity of cercosporin. Circumstantial evidence suggests that the toxic effect may be mediated by the singlet oxygen and free radical formation which induces a lipoperoxidative degradation of the polyunsaturated fatty acids of cell membranes.