The effect of herbicides on hydrogen peroxide generation in isolated vacuoles of red beet root ( Beta vulgaris L.)

Influence of herbicides on the hydrogen peroxide generation in vacuolar extracts of red beet root ( Beta vulgaris L.) was investigated. Belonging to different chemical classes of herbicide compounds have been used. Herbicides differ from each other in the mechanism of effects on plants. Clopyralid (aromatic acid herbicide, derivative of picolinic acid) and 2.4-D (phenoxyacetic herbicide), characterized by hormone-like effects, contributed to the formation of H 2O 2 in vacuolar extracts. Fluorodifen (nitrophenyl ether herbicide) and diuron (urea herbicide) also have increased contents H 2O 2. These compounds inhibit the electron transport, photosynthesis, and photorespiration in sensitive plants. Herbicidal effect of glyphosate (organophosphorus herbicide) is due to the inhibition of amino acid synthesis in plant cells. Glyphosate did not affect the content of H 2O 2 in vacuolar extracts. Herbicide dependent H 2O 2-generation did not occur with oxidoreductase inhibitors, potassium cyanide and sodium azide. The results suggest that the formation of ROS in the vacuoles due to activity of oxidoreductases, which could interact with herbicides.