A novel stress‐acclimation response in Spirodela punctata (Lemnaceae): 2,4,6‐trichlorophenol triggers an increase in the level of an extracellular peroxidase, capable of the oxidative dechlorination of this xenobiotic pollutant

摘要: Peroxidases are haem-containing enzymes capable of oxidizing a wide range substrates. This article describes the presence peroxidase activity in growth medium axenic Spirodela punctata (Lemnaceae) cultures. It was found that release extracellular is specifically enhanced by phytotoxic, halogenated phenols but not other abiotic stress-factors, elicitors or plant metabolites. Based on concentration dependence 2,4,6-trichlorophenol (TCP)-enhanced release, it concluded simply consequence physiological damage, rather requires metabolically healthy fronds. In vitro studies (UV/VIS spectroscopy and liquid chromatographylmass spectrometry) show duckweed (SpEx), which partially purified from medium, catalysing oxidative dechlorination TCP with hydrogen peroxide as electron acceptor. proposed ability S. to sense environmentally persistent phytotoxic chlorophenols, respond increasing levels their dechlorination, part protection strategy this aquatic against xenobiotic stress.