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Pseudozyma flocculosa (syn: Sporothrix flocculosa) was first discovered and described in 1987 as an epiphytic yeast on powdery mildew-infected clover leaves. It was subsequently found to be a powerful antagonist of powdery mildews which prompted its study and development as a biocontrol agent (BCA). Most BCAs exert their activity through the manifestation of one or more of the following modes of action: competition, parasitism, antibiosis and induced resistance. In the case of P. flocculosa, in vitro bioassays, electron microscopy studies, and chemical analyses all pointed to a single mode of action: antibiosis. This conclusion was reinforced by the characterization and purification of an active molecule, flocculosin, and by the demonstration of its powerful antimicrobial activity. This was further supported by the discovery of a complex gene cluster regulating the synthesis of flocculosin, a molecule nearly identical to ustilagic acid – a compound produced by U. maydis under the control of a sim...

Based on previously reported techniques and methods to identify induced phenolic compounds, a shorter, more reliable methodology for identifying conjugated plant phenolics from cucumber was developed. During the initial analytical phase of this methodology, compounds are elicited, extracted, hydrolyzed, and fractionated. During the second semipreparative phase, scale-up chromatography is used to semipurify large amounts of extracted hydrolyzed induced compound, which are later purified with semipreparative high performance liquid chromatography. To demonstrate the merits of this methodology and the problematic nature of these defence molecules, comparisons are made with the methodologies of previous studies examining phytoalexin production in cucumber plants.Key words: Cucumis sativus, induced glycosylated phenolics, phenolic acids, C-flavonoid glycosides, phytoalexins, methodology.