Cell proliferating and differentiating role of H2O2 in Sclerotium rolfsii and Sclerotinia sclerotiorum.

This study shows that the oxidant and also signal transducing H2O2 exerts a cell proliferating action at certain intracellular concentrations (around 80 nM), by inhibiting the lateral-chained and terminal sclerotial differentiation of the phytopathogenic filamentous fungi S. rolfsii and S. sclerotiorum, respectively. H2O2 also promotes sclerotial differentiation in these fungi at higher intracellular concentrations (approx. 130 nM). A cell proliferating and differentiation inhibiting effect was exerted also by the inhibitor of catalase activity aminotriazole via increase of intracellular H2O2.