Biochemical responses in the aquatic macrophyte Myriophyllum quitense exposed to the strobilurin fungicide azoxystrobin

GARANZINI, DANIELA; MENONE, MIRTA LUJÁN

Congreso; 6th SETAC World Congress 2012; 2012

Strobilurin fungicides constitute a relatively new fungicide class developed from natural fungicidal derivatives and the great impact of them on agriculture is reflected by the widespread use of azoxystrobin (AZX), a compound approved for use on more than 80 different crops. Its mechanism of toxicity is well understood in fungi but it effects in plants is scarcely studied. Aquatic macrophytes have been used as environmental biomonitors because of its important rol as bioacumulation capacity of many xenobiotics. The main goal of this study was to establish a concentration- response curve of AZX in Myriophyllum quitense, by using oxidative stress enzyme activities and chlorophyll content. Particularly the activity of Guaiacol Peroxidase (POD), Glutathione- S –Transferase (GST), Catalase (CAT), and the chlorophyll a and b contents were tested. All the parameters were measured espectrophotometrically. Plants were exposed to 0; 0,1; 1; 10; 50 and 100 ug /L of AZX for 24 hours. Inhibition of CAT and POD at 50 ug/L was observed (p0.05).). Although there was no change in the chlorophyll a/chlorophyll b ratio among treatments an increased content of both pigments at 100 ug/L with respect to control was observed (p