engleski

Potential involvement of antioxidant activity and fluorescence on Fusarium resistance and mycotoxin accumulation

Fusarium head blight is major disease affecting European cereals which is mainly caused by Fusarium graminearum and F. culmorum. These Fusarium species pose a serious threat to food safety due to their ability to produce a wide range of mycotoxins, including deoxynivalenol (DON) and zearelenone (ZEA), which can be a significant threat to the health of humans and animals. The best approach to control FHB and to reduce mycotoxin contamination is to create wheat genotypes which are carrying effective resistance genes. Effects on the physiological parameters in plants with different FHB resistance remain unclear. The objective of this study was to evaluate the activity of guaiacol peroxidase (POD) and ascorbate peroxidase (APX), catalase (CAT) and polyphenol oxidase (PPO), malondialdehide (MDA) content and hydrogen peroxide concentration. Also we wanted to evaluate the applicability of the parameters derived from the fast chlorophyll a fluorescence kinetics in order to evaluate biotic stress response of wheat and distinguish disease tolerance among the tested wheat varieties, as well as to measure some most important agronomical and technological properties of wheat. In susceptible variety Fusarium infection caused yield losses more than 35%, very high disease intensity (>100 AUDPC units), as well as Fusarium colonized kernels and initial infection. Concentrations of DON and 3-acetyldeoxynivalenol (3-ADON) in Fusarium-infected kernels in three winter varieties ranged from 68.55 to 3246.52 µg/kg and 30.87 to 501.39 µg/kg, respectively. After malting, varieties contained DON and 3-ADON (184 to 967 µg/kg and <20 to 110 µg/kg, respectively). The deacetylation of 3-ADON into DON may appear during malting process. Amount of ZEA was only detected in low amounts in infected malt and in control malt of tolerant variety. More tolerant variety was less affected by FHB infection in terms of photosynthetic function as indicated in a small reduction in performance index (PI) and maximum quantum yield of PS II (Fv/Fm), together with lower reduction in grain yield and test weight under Fusarium infection, but decrease in 1000 kernel weight occurred. In contrary, protein quality, particularly HMW-GS were the highest affected in more tolerant variety, where glutenins were decreased, but albumins and gliadins increased in infected kernels in comparison to control plants. Fusarium tolerance could be enhanced by the APX, a hydrogen peroxide detoxifying enzyme, and PPO, which has ability to oxidize flavonoids and phenolic acids induced by pathogen attack reducing thus a mycotoxin biosynthesis.

wheat ; Fusarium ; antioxidant activity ; mycotoxins

nije evidentirano