Effects of cadmium and arsenic on Pteris vittata under hydroponic conditions

Pteris vittata is known to hyperaccumulate arsenic, and a large number of studies on this fern species can be found in the literature aimed at evaluating its behavior when coexposed to other toxic elements. In the present study, P. vittata was treated with different concentrations of As and/or Cd in a hydroponic system, that is, under complete bioavailability of the elements, with the objective of investigating the effects of these two elements and their interactions. The response of the plant was evaluated by measuring As, Cd, P, and Ca concentrations in different parts of the plant. Moreover, the symptoms of phytotoxicity were assessed in terms of biomass reduction and loss of photosynthetic efficiency related to necrosis of pinnae. The concentrations of As and Cd measured in the fronds and the root system were significantly dependent on the treatment, whereas P and Ca concentrations were not affected. Interaction effects between As and Cd were observed, with maximum toxicity symptoms after treatment with both elements. This could affect the potential use of this fern for phytoremediation. Although As treatment produced a significant effect on leaves (e.g., chlorosis and necrosis), Cd treatment produced a stronger negative impact on plant health, reducing significantly the biomass and photosynthetic efficiency.