LAUSR

The present study was designed to identify the effects of ozone fumigation of red-veined sorrel plants on the selected physiological parameters and contents of bioactive compounds in the plant leaves. Sorrel plants grown in a pot experiment were subjected, at the final stage of growth, to ozone fumigation at a concentration of 1 ppm (mg m−3) for one, three, five, seven, and 10 min. The ozone treatment was followed with measurements performed one, four, and eight days later. The relative chlorophyll content in the leaves and selected chlorophyll fluorescence parameters (maximum quantum yield of PSII photochemistry, the maximum quantum yield of primary photochemistry and the performance index) and gas exchange parameters were assessed (net photosynthetic rate, transpiration rate, stomatal conductance, and intercellular CO2 concentration). By using the same leaves, the plant material was also assessed for the contents of bioactive compounds (total polyphenols) and for antioxidant properties (ABTS and DPPH assays). The ozone treatment did not produce adverse changes in the physiological parameters of the sorrel plants. Furthermore, no visible damage to the leaves was observed. On the other hand, the ozone fumigation induced the phenomenon of elicitation as a result of which it was observed that the ozone-treated sorrel plants had higher total polyphenol contents and greater antioxidant potential, compared to the plants of the same species grown in a traditional way without the ozone fumigation. Application of ozone fumigation in the production of Rumex sanguineus is associated with increased bioactive potential of the raw material obtained.