Effect of peroxisome proliferators to growth and pathogenicity of Magnaporthe oryzae

Objective: To study the effect of peroxisome proliferations (PPs) on the development and pathogenicity of rice blast fungus Magnaporthe oryzae. Methods: The peroxisomal proliferation and the expression of peroxisomal biogenesis related genes were detected in M. oryzae strain Guy11 under the induction of 6 PPs. Vegetative growth, conidial germination, appressoria formation and pathogenicity of the strain treated with PPs were compared with those of the control. Results: Induced by 6 PPs, the quantity of peroxisome and the expression of PEX14, PEX8 and PEX11 were significantly increased. Vegetative growth, conidial germination, appressorial formation and pathogenicity were inhibited by the majority of the PPs. Of them, 2, 4-D and aspirin (ASA) exhibited higher inhibition rates than others. Further, the inhibition of 2, 4-D and Aspirin to the vegetative growth of Δpex5 and Δpex7 mutants of M. oryzae was found significantly increased than that of the wild type strain. Conclusion: PPs could induce peroxisome proliferation in M. oryzae, inhibit the growth and development and reduce the pathogenicity of the fungus. This is the first investigation on the effects of PPs to filamentous fungi.