Effect of some sterol-biosynthesis-inhibiting fungicides on the biosynthesis of polyisoprenoid compounds in barley seedings.

The effect of five sterol-biosynthesis-inhibiting (SBI) fungicides, triadimefon, triarimol, diclobutrazol, tridemorph, and fenpropimorph on the germination, growth, and chloroplast pigment and sterol content of barley seedlings has been studied. Triadimefon, triarimol, and diclobutrazol at 250 microM depressed germination and growth, caused the accumulation of 14 alpha-methyl sterols, but had no effect on the formation of chlorophylls or carotenoids. Tridemorph and fenpropimorph at 250 microM had no effect on germination or the formation of chlorophylls and carotenoids but depressed growth and caused the accumulation of 9 beta,19-cyclopropyl sterols.