AbstractImmunological probes (antibodies) were raised in New Zealand White rabbits against the wood decay fungus Lentinus lepideus Fr. and thereafter employed in a variety of immunological techniques to (i) develop an immunodetection system for the fungus and (ii) to analyse L. lepideus antigens. Preliminary experiments indicated that immunological techniques could be used to detect the fungus. Nitrocellulose-based systems proved to be the most sensitive and offered the greatest potential as a routine detection system for L. lepideus.
The cross-reactivity of the L. lepideus antiserum mirrored the degree of taxonomic relatedness between L. lepideus and the fungal isolates tested. Other L. lepideus strains and Lentinus species cross-reacted most strongly followed by in descending order of magnitude, brown rot basidiomycete fungi, white rot basidiomycete fungi and deuteromycete fungi.
Wood blocks artificially infected with L. lepideus were prepared, pine (Pinus sylvestris .L) and lime (Tilia vulgaris .Hayne) being chosen as a representative softwood and hardwood respectively. Conventional weight loss studies were carried out in tandem with immunological analysis. L. lepideus could be detected within extracts from wood blocks showing no, or minimal, weight loss. Immunocytochemical and immunofluorescence techniques proved useful in mapping the spread of L. lepideus within wood block sections.
A small field trial using nine creosote-treated distribution pole stubs was established. L. lepideus was identified within core sections removed from the poles using microbiological isolation techniques and the dot-immunobinding assay. A statistically significant level of association between positive microbiological isolations of the fungus and positive reactions in the immunoassay was found.
Chemical analysis and characterisation studies of L. lepideus antigens revealed that carbohydrate is the major fungal component with significant amounts of protein also being present. The majority of the antigens are glycoproteins although some protein antigens were identified. The antigenicity of the fungus varies with age and when cultured on different growth substrates.
The application of immunological techniques to the detection and analysis of L. lepideus and the potential of such techniques as a screening system for incipient fungal decay in creosote treated distribution poles is discussed.
|Date of Award||Oct 1990|
|Supervisor||John Palfreyman (Supervisor)|