Adaptation of the phytopathogenic fungus Fusarium decemcellulare to oxidative stress

The adaptive response of the phytopathogenic fungus Fusarium decemcellulare to the oxidative stress induced by hydrogen peroxide and juglone (5-hydrox y-1,4-naphthoquinone) was studied. At concentrations higher than 1 mM, H2O2 and juglone completely inhibited the growth of the fungus. The 60-min pret reatment of logarithmic-phase cells with nonlethal concentrations of H2O2 ( 0.25 mM) and juglone (0.1 mM) led to the development of a resistance to hig h concentrations of these oxidants. The stationary-phase cells were found t o be more resistant to the oxidants than the logarithmic-phase cells. The a daptation of fungal cells to H2O2 and juglone was associated with an increa se in the activity of cellular catalase and superoxide dismutase, the main enzymes involved in the defense against oxidative stress.