Uptake arsenic by plants: Effects on mineral nutrition, growth and antioxidant capacity

Abstract

Arsenic (As) is the one of the main environmental pollutant and phytoremediation is an effective tool for its removal of the environment. In this study, Pistia stratiotes were exposed to seven As concentrations (0, 3, 7, 10, 13, 16 and 20 μM) and then, the influence of this metalloid on growth, mineral nutrition and photosynthesis were analyzed. It was observed that this species have a high affinity for As and pollutant uptake occurs rapidly. The uptake of Cu, Mn, Fe and P increased until the concentration of 13 μM, decreasing in higher concentrations.The Mg content also decreased from this same concentration. No effects were observed in the uptake of K, Ca and Zn. Growth rate and photosynthetic pigments content were negatively affected by As. Despite this decrease, the growth was maintained up to the concentration of 13 μM of As. The maintenance of growth and the change in nutrients uptake are probably related with the increase in antioxidant capacity of the plant, indicating resistance to the pollutant. In this way, P. stratiotes is probably an efficient phytoremediator of As, even when in concentrations up to one hundred times greater than those permitted in water for human consumption.