In addition to momilactone, phytocassanes A through E (diterpene phytoalexins) were detected in rice leaves in fields suffering from rice blast. Furthermore, phytocassane accumulation was most abundant at the edges of necrotic lesions, indicating that the phytoalexins prevent subsequent spread of the fungus from the infected site. In pot experiments the pattern of phytocassane accumulation in r...

Many fungal pathogens invade plants by means of specialized infection structures called appressoria. In the rice (Oryza sativa) blast fungus Magnaporthe grisea, the pathogenicity mitogen-activated protein (MAP) kinase1 (PMK1) kinase is essential for appressorium formation and invasive growth. In this study, we functionally characterized the MST7 and MST11 genes of M. grisea that are homologous ...

Magnaporthe grisea, a destructive ascomycetous pathogen of rice, secretes cell wall-degrading enzymes into a culture medium containing purified rice cell walls as the sole carbon source. From M. grisea grown under the culture conditions described here, we have identified an expressed sequenced tag, XYL-6, a gene that is also expressed in M. grisea-infected rice leaves 24 h postinoculation with ...

Marine fungi producing antifungal compounds were screened against Pyricularia oryzae (P. oryzae), and a metabolite of marine fungus M-3 isolated from laver (Porphyra yezoensis) showed potent activity. Novel diketopiperazine (1) was isolated from the culture extracts, and its structure was elucidated by spectroscopic methods. The MIC of 1 against P. oryzae was 0.36 microM.

Azospirillum lipoferum and Pyricularia oryzae laccases were compared, using several substrates and inhibitors. Sixteen phenolic or nonphenolic compounds were found to be substrates of both fungal and bacterial laccases. In the presence of different phenol oxidase inhibitors, P. oryzae and A. lipoferum laccase activities had similar properties.

The rice blast fungus Magnaporthe grisea infects its host by forming a specialized infection structure, the appressorium, on the plant leaf. The enormous turgor pressure generated within the appressorium drives the emerging penetration peg forcefully through the plant cuticle. Hitherto, the involvement of cutinase(s) in this process has remained unproven. We identified a specific M. grisea cuti...

MPG1, a pathogenicity gene of the rice blast fungus Magnaporthe grisea, is expressed during pathogenesis and in axenic culture during nitrogen or glucose limitation. We initiated a search for regulatory mutations that would impair nitrogen metabolism, MPG1 gene expression, and pathogenicity. First, we developed a pair of laboratory strains that were highly fertile and pathogenic toward barley. ...

A series of 2-(N-arylsulfonylindol-3-yl)-3-aryl-1,3-thiazinan-4-one derivatives were synthesized and evaluated in vitro against seven phytopathogenic fungi, namely Fusarium graminearum, Alternaria solani, Fusarium oxysporium f. sp. vasinfectum, Alternaria brassicae, Valsa mali, Alternaria alternata, and Pyricularia oryzae. Among all derivatives, especially compound 4j exhibited a potential anti...