AIMS   For Ophiostoma (Ceratocystis) ulmi, the ability to undergo morphological change is a crucial factor for its virulence. To gain an understanding of quorum-sensing activity in O. ulmi as it relates to yeast-mycelium dimorphism control, this study examines the effects of branched-chain amino acids as well as their fusel alcohols and fusel acids as quorum sensing molecules. METHODS AND RES...

Invasive tree pathogens threaten forests worldwide, but their effects on streams are poorly understood. Nevertheless, infections that lead to changes in the characteristics of litter inputs may affect stream communities and ecosystem processes. We studied cross-ecosystem derived from Phytophthora cinnamomi, ×alni, Ophiostoma novo-ulmi infection Castanea sativa (chestnut), Alnus lusitanica (alde...

Dutch elm disease (DED) is a destructive tracheomycosis caused by Ophiostoma novo-ulmi , an ascomycete probably originating in East-Asia that devastating natural populations throughout Europe, North America and Asia. The fungus mainly spread bark beetles complete their life cycle between healthy diseased elms. Recently, it has been highlighted some fungi of the genus Geosmithia which are simila...

Hydrophobins are components of microbial cell walls that contribute tocell surface hydrophobicity. The hydrophobic nature of the surfaces of many microbes, both prokaryotic and eukaryotic, is important to such processes as adhesion of pathogens to host structures and dispersa1 of aerial spores (Beever and Dempsey, 1978; Doyle and Rosenberg, 1990; Stringer et al., 1991). A class of peptide hydro...

In some ascomycete fungi, ribosomal protein S3 (Rps3) is encoded within a group I intron (mL2449) that is inserted in the U11 region of the mitochondrial large subunit rDNA (rnl) gene. Previous characterization of the mL2449 intron in strains of Ophiostoma novo-ulmi subspecies americana (Dutch Elm Disease) revealed a complex genes-within-genes arrangement whereby a LAGLIDADG homing endonuclease...

The nucleotide sequence (2617 nucleotides) of virus-like double-stranded (ds) RNA 3a in a diseased isolate, Log1/3-8d2 (Ld), of the ascomycete fungus Ophiostoma novo-ulmi has been determined. One strand of the dsRNA contains an open reading frame (ORF) with the potential to encode a protein of 718 amino acids, and the complementary strand contains two smaller ORFs with the potential to encode p...

ABSTRACT Twenty-one strains of Botrytis cinerea isolated from 13 species of plants grown in China were compared for pathogenicity on Brassica napus, mycelial growth on potato dextrose agar, and presence of double-stranded (ds)RNA. The results showed that the strain CanBc-1 was severely debilitated in pathogenicity and mycelial growth, compared with the 20 virulent strains. A dsRNA of approximat...