Physiological responses of Eichhornia crassipes [Mart.] Solms to the combined exposure to excess nutrients and Hg

AUTOR(ES)
FONTE

Brazilian Journal of Plant Physiology

DATA DE PUBLICAÇÃO

2009

RESUMO

In the present study the physiological response of water hyacinth (Eichhornia crassipes [Mart.] Solms) to the combined exposure of excess nutrients and Hg was examined. Young water hyacinth plants were exposed to a range of HgCl2 and KNO3 concentrations. After eight weeks, submerged plant tissues reached an Hg concentration of 4 mg g-1. The accumulation of P and S was reduced by the addition of HgCl2, and also the P and K concentrations in emerged and submerged parts decreased. In contrast, the addition of HgCl2 increased Ca and Mg concentrations in submerged parts. Furthermore, the concentration ratios of submerged/emerged parts for Ca, Mg and P were also reduced by the addition of HgCl2. The interaction of HgCl2 and KNO3 was synergistic and decreased Fv/Fm, total chlorophyll content and P and Mn concentrations in emerged parts. In submerged plant parts Ca concentration increased and K content stabilized as a result of the above interaction. However, the total accumulation of Hg per plant was not reduced, thereby confirming the water hyacinth as a promising candidate for the heavy metal phytoremediation of eutrophic waters.

Documentos Relacionados