Production of a monoclonal antibody specific to the genus Trichoderma and closely related fungi, and its use to detect Trichoderma spp. in naturally infested composts

• Published in: Microbiology (Society for General Microbiology) 2002-05, Vol.148 (5), p.1263-1279
• Main Authors: Thornton, Christopher R, Pitt, Dennis, Wakley, Gavin E, Talbot, Nicholas J
• Format: Article
• Language: English
• Subjects: Antibodies, Fungal - biosynthesis; Antibodies, Fungal - immunology; Antibodies, Monoclonal - biosynthesis; Antibodies, Monoclonal - immunology; Antibody Specificity; Antigens, Fungal - immunology; Biological and medical sciences; DNA, Intergenic - genetics; Enzyme-Linked Immunosorbent Assay; Fundamental and applied biological sciences. Psychology; Gliocladium viride; Glucan 1,4-alpha-Glucosidase; Glucans; Glucose - metabolism; Growth, nutrition, metabolism, transports, enzymes. Molecular biology; Hybridomas; Hypocrea; Hypomyces chrysospermus; Microbiology; Microscopy, Immunoelectron; Mitosporic Fungi - genetics; Mitosporic Fungi - immunology; Mitosporic Fungi - isolation & purification; Mitosporic Fungi - ultrastructure; Molecular Sequence Data; Mycelium - growth & development; Mycelium - immunology; Mycelium - metabolism; Mycological Typing Techniques; Mycology; Phylogeny; Polysaccharides - metabolism; RNA, Ribosomal - analysis; Soil Microbiology; Sphaerostilbella; Trichoderma; Trichoderma - genetics; Trichoderma - immunology; Trichoderma - isolation & purification; Trichoderma - ultrastructure; Tumor Cells, Cultured; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/00221287-148-5-1263

Washington Singer Laboratories, School of Biological Sciences, University of Exeter, Perry Road, Exeter, Devon EX4 4QG, UK 1 Author for correspondence: Christopher R. Thornton. Tel: [phone]. Fax: [phone]. e-mail: C.R.Thornton{at}ex.ac.uk Studies of the interactions between hyperparasitic fungi and their hosts are severely hampered by the absence of methods that allow the unambiguous identification of individual genera in complex environments that contain mixed populations of fungi, such as soil or compost. This study details the development of a monoclonal antibody (MF2) that allows the detection and recovery of Trichoderma spp. in naturally infested composts, and the visualization of hyperparasitic strains of Trichoderma during antagonistic interactions with their hosts. Murine monoclonal antibody MF2, of immunoglobulin class M (IgM), was raised against a protein epitope of a glycoprotein antigen(s) specific for species of the genus Trichoderma and for the closely related fungi Gliocladium viride , Hypomyces chrysospermus , Sphaerostilbella spp. and Hypocrea spp. MF2 did not react with antigens from Gliocladium catenulatum , Gliocladium roseum , Nectria ochroleuca and Clonostachys spp., nor with a range of unrelated soil- and compost-borne fungi. Extracellular production of the MF2 antigen was constitutive. Western-blotting analysis showed that MF2 bound to a ladder of proteins with apparent molecular masses in the range 35–200 kDa. Immunofluorescence studies showed that MF2 bound strongly to the cell walls of hyphae and phialides and the intercalary and terminal chlamydospores of Trichoderma spp., whereas immunogold electron microscopy revealed strong binding of MF2 to the cell walls and septa of hyphae and to the cell walls of phialoconidia. In immunofluorescence studies of dual cultures of Trichoderma and Rhizoctonia solani , only the cell walls of the hyperparasite, which coiled around the host, were stained by MF2. The specificity of MF2 enabled the development of a combined baiting–ELISA technique for the detection of Trichoderma spp. in naturally infested composts. The specificity of this technique was confirmed by phylogenetic analysis based on sequences of the ITS1–5·8S–ITS2 rRNA-encoding regions of the isolates. Keywords: Gliocladium , ß-1,3-glucanase, glucoamylase, ITS region Abbreviations: IF, immunofluorescence; ITS, internally transcribed spacer; PAS, periodic acid Schiff