Sulfur metabolism: different tolerances of two aquatic macrophytes exposed to arsenic.

摘要: Abstract The toxicity of arsenic (As) and the mechanisms response to this pollutant were analyzed in two aquatic plant species, one sensitive tolerant pollutant, Salvinia minima Lemna gibba , respectively. plants, grown nutrient solution at pH 6.5, exposed As concentrations 0.0 1.0 mg L −1 for 3 days. Both species accumulated their tissues, which resulted increases H 2 O production. L. eleven times more than S. . However, was tolerant, as shown by absence cell membrane damage and, despite greater accumulation, smaller growth reduction Indeed, index tolerance twenty percent higher most likely results from presence a efficient defense system. This system is based on sulfate absorption, assimilation metabolism. showed an increase absorption adenosine-5′-triphosphate (ATP) sulfurylase activity (the first enzyme inorganic pathway) following exposure As. Consequently, produced sulfur-containing compounds that are involved cellular detoxification, such glutathione non-protein thiols, demonstrated enzymatic γ-glutamylcysteine synthetase, S-transferase reductase. Therefore, plant׳s ability metabolism sulfur key steps oxidative stress triggered metals.