Induction of Fusarium lytic Enzymes by Extracts from Resistant and Susceptible Cultivars of Pea (Pisum sativum L.)

Recent advances in the combinations of plant-sourced natural products for the prevention of mycotoxin contamination in food

Mycotoxins, secondary metabolites produced by mycotoxigenic fungi, are a major problem affecting food safety and security, because of their adverse health effects, their socio-economic impact and the difficulty of degradation or removal by conventional food processing methods. Plant-sourced natural products are a novel and effective control method for fungal infestation and mycotoxin production, with the advantages of biodegradability and acceptability for food use. However, development of resistance, low and inconsistent efficacy, and a limited range of antifungal activities hinder the effective application of single plant natural products for controlling mycotoxin contamination. To overcome these limitations, combinations of plant natural products have been tested extensively and found to increase efficacy, often synergistically. However, this extensive and promising research area has seen little development of practical applications. This review aims to provide up-to-date information on the antifungal, anti-mycotoxigenic and synergistic effects of combinations of plant natural products, as well as their mechanisms of action, to provide a reference source for future research and encourage application development.

Dynamics of Fusarium Mycotoxins and Lytic Enzymes during Pea Plants' Infection

Fusarium species are common plant pathogens that cause several important diseases. They produce a wide range of secondary metabolites, among which mycotoxins and extracellular cell wall-degrading enzymes (CWDEs) contribute to weakening and invading the host plant successfully. Two species of Fusarium isolated from peas were monitored for their expression profile of three cell wall-degrading enzyme coding genes upon culturing with extracts from resistant (Sokolik) and susceptible (Santana) pea cultivars. The extracts from Santana induced a sudden increase in the gene expression, whereas Sokolik elicited a reduced expression. The coherent observation was that the biochemical profile of the host plant plays a major role in regulating the fungal gene expression. In order to uncover the fungal characteristics in planta, both pea cultivars were infected with two strains each of F. proliferatum and F. oxysporum on the 30th day of growth. The enzyme activity assays from both roots and rhizosphere indicated that more enzymes were used for degrading the cell wall of the resistant host compared to the susceptible host. The most commonly produced enzymes were cellulase, β-glucosidase, xylanase, pectinase and lipase, where the pathogen selectively degraded the components of both the primary and secondary cell walls. The levels of beauvericin accumulated in the infected roots of both cultivars were also monitored. There was a difference between the levels of beauvericin accumulated in both the cultivars, where the susceptible cultivar had more beauvericin than the resistant one, showing that the plants susceptible to the pathogen were also susceptible to the toxin accumulation.