engleski

Toxicity of mycotoxin fumonisin B1 to duckweed (Lemna minor L.)

Mycotoxin fumonisin B1 (FB1) is produced by moulds from Fusarium genera and is found as a contaminant on cereals all around the world. FB1 is toxic to domestic and experimental animals and development of some human diseases is associated with exposure to this mycotoxin. International Agency for Research on Cancer classified FB1 as a group 2B carcinogen. Although FB1 is found in environment, its impact on plants is not studied thoroughly. The aim of this study was to test toxicity and oxidative stress as mechanism of toxicity of mycotoxin FB1 on duckweed (Lemna minor L.). Duckweed was treated with FB1 (0.5 and 1 mg L-1) for 3 days. Toxicity was assessed in terms of growth rate (based on either frond number or fresh weight) and content of photosynthetic pigments (chlorophyll a, chlorophyll b and carotenoids). Malondialdehyde (MDA), non-protein thiols, antioxidant enzymes activities, level of glutathione and reactive oxygen species in situ were evaluated as parameters of oxidative stress. FB1 reduced grow rate for 16% and 21%, at 0.5 and 1 mg l-1 treatment, respectively (p<0.05), but had no effect on the level of photosynthetic pigments. Ascorbate peroxidase activity increased (for 30% after 0.5 mg L-1 treatment and for 46% after 1 mg L-1 treatment ; p<0.05) while activity of catalase decreased (for 18% after 0.5 mg L-1 treatment and for 12% after 1 mg L-1 treatment ; p<0.05). Obtained results indicate that FB1 is toxic to duckweed and that oxidative stress is involved in the mechanism of its toxicity.

mycotoxin ; experimental model ; environment ; photosynthetic pigments ; oxidative stress

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