Polyketide exometabolites of the causative agent of rice blast and their role in pathogenesis

A polyketide exometabolite — 3,4,8-trihydroxy-3,4-dihydronaphthalen-1(2H)-one (3,4,8-TDH) — has been isolated from the culture liquids of four isolates of the phytopathogenic fungusPiricularia oryzae Cavara. It has been shown that all the natural isolates investigated, and also nonpathogenic rose mutants and a series of dwarf mutants synthesize 3,4,8-TDH. This substance was not detected in filtrates of cultures of albino mutants. One of the natural isolates produces, together with 3,4,8-TDH, another polyketide — piriculol. The role in pathogenesis of the exometabolites isolated is discussed.All-Union Scientific-Research Institute of Phytopathology of Gosagroprom SSR. Golitsyno. V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 572–577, July–August, 1988.