Phytosterol biosynthesis in wheat as influenced by diclobutrazol

ABSTRACT

Diclobutrazol, a new systemic fungicide which acts as ergosterol biosynthesis inhibitor [EBI], when applied as soil drench at high concentration [250 uM] retarded the growth of wheat [cv. 'Aquila'] seedlings. The 14 -demethylation and the second transmethylation reactions in phytosterol biosynthesis were also affected, but not to the extent to be phytotoxic. Hence growth retardation was not related to the inhibition of phytosterol biosynthesis. It was much due to a diminished gibberellins biosynthesis. These effects are discussed with reference to the fungicide interaction with cytochrome P - 450 monoxygenases in the plant systems