The consequences of inhibition of ergosterol biosynthesis in Sclerotinia sclerotiorum (Lib) de Bary by Hexaconazole

Abstract

Sclerotinia sclerotiorum (Lib) de Bary is one of the most non-specific, and ubiquitous fungal plant pathogens affecting agricultural crops. This is known to cause some important diseases like white mold, Sclerotinia wilt or stalk rot, or Sclerotinia head rot on a wide variety of broadleaf crops. This pathogen infects about 408 species of plants. The brief study with S. sclerotiorum and its control with hexaconazole, (ergosterol biosynthesis inhibitor) revealed that the fungicide is a potential antifungal and that it affects the biology of the pathogen in a variety of ways. It directly affects the cell and can bring about growth inhibition by impairing one or the other of the vital phenomena. All the vital functions of the fungus appear to have been impeded. The study also revealed that the mode of action of fungicide is not only by inhibiting ergosterol biosynthesis but probably also by an ancillary mode by photo-oxidation of ergosterol wherein, hexaconazole acted as a photo-sensitizer. This study also reveals that hexaconazole, exerted an excellent fungistatic effect at 100 μg/mL concentration on S. sclerotiorum.   Therefore, this fungicide could be effectively used for control of the notorious pathogen, S. sclerotiorum at a time when many pathogens are acquiring resistance to different classes of fungicides.