Antioxidant system of ginseng under stress by cadmium

Abstract

Toxic levels of Cd can cause protein denaturation and oxidative stress, which result in membrane damage, enzimatic activity changes and other metabolic damage. Some plants may show alteration in the activity of their antioxidant enzymes as a heavy metal tolerance mechanism. This study aims at evaluating the role of enzymes of the antioxidant system in adaptive responses of the accumulator P. glomerata species to levels of cadmium (Cd). Plants were cultivated in nutrient solutions containing concentrations of Cd in the form of CdSO4 (0, 45 and 90 µmol L-1), for 20 d. Cd concentrations and yields of root and shoot dry matter were determined at the end of the experiment. Malondialdehyde (MDA) production and the activities of antioxidant enzymes were determined after days 1, 12 and 20. Higher Cd concentrations in tissues of P. glomerata were found to reduce biomass production in both roots and shoots. The lipid peroxidation rates in leaves and roots were smaller at the start of the experiment for all Cd levels. Superoxide dismutase (SOD) activity increased in leaves on day 1 and in roots on day 20 as Cd levels increased. Cd stress induced an increase in the activity of APX in leaves, whereas in roots ascorbate peroxidase (APX) activity was reduced at high concentration of Cd. At the end of the experiment, catalase (CAT) activity in leaves was reduced as Cd concentration increased. Nevertheless, the glutathione reductase (GR) and guaiacol peroxidase (GPX) activities increased. In roots, GR activity was reduced on days 1 and 20

Trace Elements Tolerance Modulated by Antioxidant System in Plants

“…In regard to GR, when M. urundeuva and P. glomerata were exposed to Zn and Cd, respectively, GR demonstrated a trend similar to APX (Gomes et al, 2013c;Marques and Soares, 2011). These results would be expected as GR and APX are linked through the glutathione-ascorbate (AsA-GSH) cycle.…”

Responses of Ruderal Verbascum olympicum Boiss. (Scrophulariaceae) Growing under Cadmium Stress

“…SOD is the first enzyme in the detoxification process that rapidly converts O 2 •− radicals to H 2 O 2 . Some studies report the inhibition of the activity of this enzyme in some plants species whereas other reports indicate that Cd induced the activity of this enzyme . The increase in SOD activity can be attributed to an induction of the expression of genes encoding SOD by superoxide radical accumulation and the de novo synthesis of other enzymes .…”

“…•À radicals to H 2 O 2 [13]. Some studies report the inhibition of the activity of this enzyme in some plants species [15,51] whereas other reports indicate that Cd induced the activity of this enzyme [67].…”

Antioxidative responses of Pseudomonas fluorescens YZ2 to simultaneous exposure of Zn and Cefradine

“…Cefradine were analyzed (*p \ 0.05 significant,**p \ 0.01 highly significant) toxicity. Marques and Soares (2011) found that SOD of the antioxidant system was stimulated to decrease the oxidant stress in P. glomerata species with the increase of cadmium (Cd). The response of antioxidant system was also different, for example, though ROS production can be slowed due to the absence of oxygen, a higher rate of ROS formation was also associated with the significantly higher concentrations of heavy metals (Fe, Al, Zn), a lower level of SOD was conserved in the limpet living in the heavy metals polluted area no matter hypoxia or air exposure (Weihe et al 2010).…”

“…Cefradine. Oxidant pressure caused by the overproduction of ROS could destroy the biological protein and cytomembrane, even change the activity of some enzyme (Marques and Soares 2011). Chopra et al (2013) had compared the proteome of the multidrug resistant strain BAA-1605 with that of the drug-sensitive strain ATCC 17978 by large-scale quantitative proteomics and found that 114 of 1484 proteins were more abundant and 99 were less abundant.…”