SciELO - Scientific Electronic Library Online

vol.31 issue2Different physiological responses under drought stress result in different recovery abilities of two tropical woody evergreen speciesTemporal evaluation of the Conservation Priority Index for medicinal plants author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand




Related links


Acta Botanica Brasilica

Print version ISSN 0102-3306On-line version ISSN 1677-941X


LEAO, Gabriela Alves; OLIVEIRA, Juraci Alves de; FELIPE, Rafaella Teles Arantes  and  FARNESE, Fernanda Santos. Phytoremediation of arsenic-contaminated water: the role of antioxidant metabolism of Azolla caroliniana Willd. (Salviniales). Acta Bot. Bras. [online]. 2017, vol.31, n.2, pp.161-168.  Epub May 02, 2017. ISSN 0102-3306.

Phytoremediation has proven to be an efficient technology for removing arsenic (As) from water, but the plants used in this process need to be tolerant to the damage caused by As. The toxic effect of As on growth and functioning of the antioxidant system was studied in individual plants of Azolla caroliniana exposed to five concentrations of As (0.0, 0.25, 0.5, 1.0 and 1.5 mg L-1) for the course of five days. Growth, As absorption, enzymatic activity, total and non-protein thiols and anthocyanin content were assessed. Azolla caroliniana was able to take up large amounts of the pollutant, reaching As concentrations of 386.1 µg g-1 dry weight without saturating the absorption mechanism. The tolerance index and the growth of A. caroliniana decreased with the increased As uptake. Superoxide dismutase, peroxidases, catalases and glutathione reductase activities increased at lower doses of As and subsequently declined with higher concentrations, whereas ascorbate peroxidase activity was reduced in all treatments. Unlike the enzymatic defence system, anthocyanin and thiol content increased consistently in all treatments and showed a positive correlation with As concentration. Therefore, the increased synthesis of non-enzymatic antioxidants is most likely the main factor responsible for the high As tolerance of A. caroliniana.

Keywords : anthocyanin; antioxidant enzymes; aquatic plant; thiol compounds; water remediation.

        · text in English     · English ( pdf epdf )