EFFECT OF MEPANIPYRIM ON UPTAKE OF VARIOUS SUBSTRATES AND MACROMOLECULAR BIOSYNTHESES IN BOTRYTIS-CINEREA

Mepanipyrim, N-(4-methyl-6-prop-1-ynylpyrimidin-2-yl)aniline, hardly i nhibited the mycelial respiration and the syntheses of DNA, RNA, prote in, lipids and cell walls in mycelia of Botrytis cinerea at 100 mug/ml . By the treatment of mepanipyrim at 10-100 mug/ml, each uptake of C-1 4-labeled glucose, acetate, uridine, thymidine, alanine or glucosamine by the mycelia of B. cinerea was inhibited, but no apparent uptake in hibition of these precursors was observed below 1 mug/ml. The inhibiti on by mepanipyrim of the active transport process across the cellular membrane may bring about a chronic deficiency in most intracellular su bstrates essential for growth and development. However, the effect of mepanipyrim appeared not to be strong enough to disrupt the overall fu nctions of cell membrane in B. cinerea; because it neither stimulated the leakage of protein, phosphate, glucose and electrolytes from the c ells, nor influenced the bursting rate of protoplasts by osmotic shock .