Use of the Secreted Proteome of Trametes versicolor for Controlling the Cereal Pathogen Fusarium langsethiae.

Fusarium langsethiae is amongst the most recently discovered pathogens of small grains cereals. F. langsethiae is the main producer, in Europe, of T2 and HT-toxins in small grain cereals, albeit often asymptomatic; this makes its control challenging. The European Union (EU) is pushing hard on the use of biocontrol agents to minimize the use of fungicides and pesticides, which are detrimental to the environment and responsible for serious pollution of the soil and superficial water. In line with EU directives (e.g., 128/2009), here we report the use of protein fractions, purified from the culture filtrate of the basidiomycete Trametes versicolor, for controlling F. langsethiae. T. versicolor, a so-called medicinal mushroom which is applied as a co-adjuvant in oncology and other pathologies as a producer of biological response modifiers. In this study, the exo-proteome of T. versicolor proved highly efficient in inhibiting the growth of F. langsethiae and the biosynthesis of the T2 toxin. Results are promising for its future use as a sustainable product to control F. langsethiae infection in cereals under field conditions.

A multi-methodological approach in the study of Italian PDO "Cornetto di Pontecorvo" red sweet pepper.

A multi-methodological approach was applied to study red sweet peppers (Capsicum annuum L.) ecotype "Cornetto di Pontecorvo" grown in a greenhouse or in open field. This approach includes morphological analysis, chemical composition determination, and biological activity evaluation of different extracts from pepper fruits. Untargeted analyses, namely NMR spectroscopy and mass spectrometry, allowed the comprehensive pepper metabolite profile of pepper pulp, peel and seeds hydroalcoholic and organic extracts to be determined, showing the presence of sugars, organic acids, amino acids and other secondary metabolites. Targeted analyses, such as HPLC-PDA, HPLC-TLC and spectrophotometric analyses allowed polyphenols, tannins, flavonoids and pigments content to be determined. Samples quality and freshness were verified by the low content of biogenic amines and mycotoxins, as determined using HPLC-FLD and HPLC-MS, respectively. Preliminary biological results demonstrated the ability of the organic extracts to inhibit α-amylase, a key enzyme in the control of glucose metabolism.

Tramesan, a novel polysaccharide from Trametes versicolor. Structural characterization and biological effects.

Mushrooms represent a formidable source of bioactive compounds. Some of these may be considered as biological response modifiers; these include compounds with a specific biological function: antibiotics (e.g. plectasin), immune system stimulator (e,g, lentinan), antitumor agents (e.g. krestin, PSK) and hypolipidemic agents (e.g. lovastatin) inter alia. In this study, we focused on the Chinese medicinal mushroom "yun zhi", Trametes versicolor, traditionally used for (cit.) "replenish essence and qi (vital energy)". Previous studies indicated the potential activity of extracts from culture filtrate of asexual mycelia of T. versicolor in controlling the growth and secondary metabolism (e.g. mycotoxins) of plant pathogenic fungi. The quest of active principles produced by T. versicolor, allowed us characterising an exo-polysaccharide released in its culture filtrate and naming it Tramesan. Herein we evaluate the biological activity of Tramesan in different organisms: plants, mammals and plant pathogenic fungi. We suggest that the bioactivity of Tramesan relies mostly on its ability to act as pro antioxidant molecule regardless the biological system on which it was applied.

Genotypic and phenotypic versatility of Aspergillus flavus during maize exploitation.

Aspergillus flavus is a cosmopolitan fungus able to respond to external stimuli and to shift both its trophic behaviour and the production of secondary metabolites, including that of the carcinogen aflatoxin (AF). To better understand the adaptability of this fungus, we examined genetic and phenotypic responses within the fungus when grown under four conditions that mimic different ecological niches ranging from saprophytic growth to parasitism. Global transcription changes were observed in both primary and secondary metabolism in response to these conditions, particularly in secondary metabolism where transcription of nearly half of the predicted secondary metabolite clusters changed in response to the trophic states of the fungus. The greatest transcriptional change was found between saprophytic and parasitic growth, which resulted in expression changes in over 800 genes in A. flavus. The fungus also responded to growth conditions, putatively by adaptive changes in conidia, resulting in differences in their ability to utilize carbon sources. We also examined tolerance of A. flavus to oxidative stress and found that growth and secondary metabolism were altered in a superoxide dismutase (sod) mutant and an alkyl-hydroperoxide reductase (ahp) mutant of A. flavus. Data presented in this study show a multifaceted response of A. flavus to its environment and suggest that oxidative stress and secondary metabolism are important in the ecology of this fungus, notably in its interaction with host plant and in relation to changes in its lifestyle (i.e. saprobic to pathogenic).