Biochemical characterization of a sterol mutant plant regenerated from a tobacco callus resistant to a triazole cytochrome-P-450-obtusifoliol-14-demethylase inhibitor.

We report here, for the first time, the biochemical characterization of a plant mutant impaired in sterol biosynthesis. A fertile plant was regenerated from a tobacco callus resistant to LAB170250F, a potent inhibitor of the cytochrome-P450-obtusifoliol-14-demthylase. The resistant callus and the leaves from the regenerated plant are characterized by profound qualitative and quantitative changes in their sterol content. Self-fertilization of this plant yielded seeds with the same biochemical features, indicating that the new phenotype is of mutational origin.