The cellular redox state as a modulator in cadmium and copper responses in Arabidopsis thaliana seedlings

Role of ROS and auxin in plant response to metal-mediated stress

“…7,[17][18][19] For metal stress, many metals such as Cd, Cu, Fe, Zn, Hg, Mn and Al can induce the ROS production 11,13,[20][21][22] and ROS scavenging systems, including catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxide (APX) and glutathione reductase (GR) often work in the protection against excess ROS toxicity in plants. 11,13,17,18,23 Hg has negative effect on algae growth and stimulates ROS production. To avoid the Hg-induced oxidative stress, antioxidative enzymes such as SOD, CAT and APX are upregulated to diminish the excess ROS.…”

“…11 A similar effect is also reported by Cd, in which the enzyme activities of CAT, APX and GR are increased both in the roots and leaves of Cd-exposed plants. 13 …”

“…13 In addition, the antioxidative enzyme activities are differentially regulated in roots and leaves after Cu-exposure, for example, CAT activity is decreased in the roots, but increased in the leaves of Cu-treated plants. 13 In addition to causing oxidative stress, ROS can also serve as a signal molecule for plants to survive in harsh conditions such as metal stress.…”

“…[4][5][6][7][8][9] Recent research has revealed that metal-mediated stress seems to have a direct impact on accumulation of relative oxygen species (ROS), content of nitric oxide (NO) and hormone levels in organs and the plants can quickly adjust their growth to harsh environment by influencing the cellular redox state and hormone signaling. [10][11][12][13][14][15][16] This review provides an update on the regulation of plant responses to metal-stress by ROS and auxin signaling pathway, primarily, with a focus on the copper, aluminum and cadmium stress. The mechanisms underlying how metal stress modulates the changes in auxin distribution and the network of ROS and auxin in plant response to metal stress are discussed based on recent studies.…”

The mechanisms of detoxification of As(III), dimethylarsinic acid (DMA) and As(V) in the microalga Chlorella vulgaris

“…However, as a redox-inactive stressor, only As(III) can inhibit enzymatic activities as a result of its affinity for −SH groups. In contrast, As(V) does not have such strong affinity for −SH and therefore, strictly speaking, should not be considered an oxidative stressor unless enzymatic reduction takes place (Cuypers et al, 2011;Mishra et al, 2006). In such cases, GSH plays an important role as a reducing agent, a scavenger of reactive oxygen species, substrate of PC formation and a redox buffer.…”