Effect of arsenic on some physiological parameters in bean plants

The objective of the study was to investigate the effect of different arsenic concentrations on some physiological parameters of bean (Phaseolus vulgaris L.) cultivars Plovdiv 10 and Prelom in the early growth phases. Seedlings, grown in sand with Hoagland-Amon nutrient solution in a climatic box, were treated with 0, 2, 5 mg(As) dm(-3) as Na3AsO4 (pH 5.5). After 5 d of As treatment, the changes in leaf gas-exchange, water potential, chlorophyll and protein contents, peroxidase activity and lipid peroxidation in roots were recorded. Physiological analysis showed a minor negative effect of arsenic at concentration 2 mg(As) dm(-3), but at the higher dosage of 5 mg(As) dm(-3) growth, leaf gas-exchange, water potential, protein content and biomass accumulation were reduced in both cultivars. The peroxidase activity and lipid peroxidation increased considerably at 5 mg(As) dm(-3), which is a typical reaction of the plants to a presence of oxidative stress.