Author/Editor		Razinger, Jaka; Drinovec, Luka; Zrimec, Alexis
Title		Real-time visualization of oxidative stress in a floating macrophyte Lemna minor L. exposed to cadmium, copper, menadione, and AAPH
Type		članek
Source		Environmental toxicology
Publication year		2009
Language		eng
Abstract		An ultra-sensitive digital imaging system was employed to visualize oxidative stress in intact L. minor plants exposed to Cd, Cu, menadione, AAPH, and ascorbate in real time. The increase of ROS production was assessed by measuring the rate of fluorescence intensity increases of the test medium supplemented with a fluorescing probe (dichlorofluorescein diacetate). The addition of 100 M CdCl2 or 100 M CuSO4 to the growth medium resulted in a significant increase of medium fluorescence. Additionally, CuSO4 caused a significantly higher fluorescence intensity than CdCl2 did. A strong positive correlation (R2 = 0.99) between menadione concentration and fluorescence intensity was observed. The positive correlation between AAPH concentration and fluorescence intensity was not as strong as in the case of menadione (R2 = 0.81). Menadione induced a stronger oxidative stress than similar concentration of AAPH. The addition of 100 M ascorbate to L. minor treated with 50 M menadione significantly reduced the fluorescence intensity increase. A linear trend of the fluorescence increase was observed in all treatments, indicating that chemical-induced oxidative stress is a gradual process and that the applied concentrations of the chemicals caused a constant increased production of ROS with different intensities, depending on the treatment. This is the combined result of a gradual diminishing of antioxidant reserves and accumulating oxidative damage. The observed rates of ROS production were slower than those in the studies using cell cultures.
Descriptors		PLANTS OXIDATIVE STRESS CADMIUM COPPER VITAMIN K ASCORBIC ACID CULTURE MEDIA REACTIVE OXYGEN SPECIES FLUORESCENT DYES FLUORESCENCE