Zinc ameliorates copper-induced oxidative stress in developing rice (Oryza sativa L.) seedlings

Abstract

Rice (Oryza sativa L.) seedlings were treated with different concentrations of copper (Cu) either in presence or absence of zinc (Zn), and different events were investigated to evaluate the ameliorative effect of Zn on Cu stress. In presence of high Cu concentration, growth of both root and shoots were considerably reduced. Decline in elongation and fresh mass was observed in root and shoot. Zn alone did not show any considerable difference as compared to control, but when supplemented along with high concentration Cu, it prompted the growth of both root and shoot. After 7 days, root growth was 9.36 and 9.59 cm, respectively, at 200 and 500 μM of Cu alone as compared to 10.59 and 12.26 cm at similar Cu concentrations, respectively, in presence of Zn. Cu accumulation was considerably high after 7 days of treatment. In absence of Zn, significant accumulation of Cu was observed. Zn supplementation ameliorated the toxic impact of Cu and minimized its accumulation. Cu treatment for 1 and 7 days resulted in a dose-dependent increase in hydrogen peroxide (H2O2). When Cu was added in presence of Zn, the H2O2 production in root and shoot was reduced significantly. The increase in H2O2 production under Cu stress was accompanied by augmentation of lipid peroxidation. In absence of Zn, Cu alone enhanced the malondialdehyde (MDA) production in both root and shoot after 1 and 7 days of treatment. The MDA content drastically reduced in root and shoot as when Zn was added during Cu treatment. The activities of antioxidant enzymes like superoxide dismutase (SOD), catalase (CAT), and guaiacol peroxidase (GPX) were elevated under Cu stress both in root and shoot. Addition of Zn further stimulated the activities of these enzymes. Both ascorbate (AsA) and glutathione (GSH) contents were high under Cu stress either in presence or absence of Zn. The results suggests that Zn supplementation improves plant survival capacity under high Cu stress by modulating oxidative stress through stimulation of antioxidant mechanisms and restricts the accumulation of toxic concentrations of Cu.

Drought stress tolerance mediated by zinc-induced antioxidative defense and osmotic adjustment in cotton (Gossypium Hirsutum)

“…5a-c), suggesting that supplemental Zn efficiently enhanced the ability of antioxidant defense, which contributed to alleviate oxidative injuries under PEG-6000 simulated drought stress. Similar reports have also shown that Zn ameliorates oxidative stress caused by excessive copper by enhancing SOD, CAT and APX activities in developing rice seedlings (Thounaojam et al 2014).…”

“…The AsA and GSH regeneration system is also required for the conversion of H 2 O 2 to H 2 O by APX via ascorbate-glutathione cycle (Choudhury et al 2013). Enhanced AsA and GSH contents by supplemental Zn were involved in ameliorating copperinduced oxidative stress in rice (Thounaojam et al 2014). Supplemental Zn dramatically enhanced AsA and GSH accumulations in cotton leaves under PEG-6000 simulated drought stress (Fig.…”

“…In addition, this element is also very important in maintaining the biomembrane structure and for detoxifying ROS (Rehman et al 2012). Besides, several previous studies have been observed that various abiotic stresses were mediated by supplemental Zn, such as cold, heat, drought, heavy metals, and salt stress (Li and Yu 2008;Qu et al 2009;Peck and McDonald 2010;Zhao et al 2011;Upadhyaya et al 2013; Thounaojam et al 2014). Many previous studies have investigated that Zn mediated drought tolerance in several plants, such as red cabbage (Hajiboland and Amirazad 2010), tomato (Sadoogh et al 2014), sunflower (Eslami and Dehghanzadeh 2014), winter wheat (Karim et al 2012), tea (Upadhyaya et al 2013).…”

Ameliorative effect of Yeast Extract, IAA and Green-synthesized Nano Zinc Oxide on the Growth of Cu-stressed Vicia faba Seedlings

“…The recorded increase in total soluble carbohydrates and protein on priming with Nano ZnO was in accordance with the findings of Venkatachalam et al (2016) using Nano ZnO under Cd or Pb stress in Leucaena leucocephala seedlings and with those of Soliman et al (2015) using nano-iron and nano-zinc in salt stressed Moringa peregrina plants. This resultant increase might be due tothe involvement of Zn in the structure of various enzymes and transcriptional factors with important roles in protein and carbohydrate synthesis and regulation of nucleic acids and lipid metabolism (Bonnet et al, 2000 andThounaojam et al, 2013).…”

Bacterial Detoxification of Copper and Its Impacts on Germination Indices of Barley and Mung Bean

“…The ionic form of Cu 2+ caused root growth alterations in durum wheat at low concentration; 1.0 μM and high Cu concentrations (200 and 500 μM) may reduce the growth of both root and shoots (Michaud et al, 2008 andThounaojam et al, 2014). Toxicity of Cu is affected by bioavailability of metal in the soil and by the concentration of the metal as well as pH of the soil (Wang et al, 2009).…”