Plant-extract-induced changes in the proteome of the soil-borne pathogenic fungus 'Thielaviopsis basicola'

Abstract

'Thielaviopsis basicola' is a hemibiotroph fungus that causes black root rot disease in diverse plants with significant impact on cotton production in Australia. To elucidate how 'T. basicola' growth and proteome are influenced by interactions with natural sources, this fungus was cultured in the presence of root extracts from non-host (wheat, hairy vetch) and susceptible host (cotton, lupin) plants. We found that 'T. basicola' growth was significantly favored in the presence of host extracts, while hierarchical clustering analysis of 2-DE protein profiles of 'T. basicola' showed plant species had a larger effect on the proteome than host/non-host status. Analysis by LC-MS/MS of unique and differentially expressed spots and identification using cross-species similarity searching and 'de novo' sequencing allowed successful identification of 41 spots. These proteins were principally involved in primary metabolism with smaller numbers implicated in other diverse functions. Identification of several "morpho" proteins suggested morphological differences that were further microscopically investigated. Identification of several highly expressed spots suggested that vitamin B6 is important in the 'T. basicola' response to components present in hairy vetch extract, and finally, three spots, induced in the presence of lupin extract, may correspond to malic enzyme and be involved in lipid accumulation.