Antioxidant responses of barley ( Hordeum vulgare L.) genotypes to lead toxicity
- PDF / 743,543 Bytes
- 8 Pages / 595.276 x 790.866 pts Page_size
- 53 Downloads / 192 Views
ORIGINAL ARTICLE
Antioxidant responses of barley (Hordeum vulgare L.) genotypes to lead toxicity Ali Doğru 1 Received: 28 December 2019 / Accepted: 7 May 2020 # Plant Science and Biodiversity Centre, Slovak Academy of Sciences 2020
Abstract The effects of lead toxicity were studied in the leaves of two barley cultivars. Plants were grown for 32 days in perlite and then exposed to 10- and 15-mM Pb(NO3)2 for additional 6 days. Lead toxicity decreased the photosynthetic pigment contents in the leaves of Tokak 157/37. The phenolic content of the leaves was reduced in Tarm-92 and increased in Tokak 157/37. The malondialdehyde content in leaves showed that lipid peroxidation in Tokak 157/37 was lower than in Tarm-92. H2O2 accumulation was more remarkable in the leaves of Tokak 157/37 exposed to 15 mM lead. Significantly higher superoxide dismutase activity observed in our study indicates a likely higher rate of superoxide radical dismutation. Lower ascorbate peroxidase activities were observed at 10 mM lead in Tarm-92 and at 15 mM lead in Tokak 157/37. The glutathione reductase activity in Tarm-92 was lower whereas it was induced by 10 mM lead treatment in Tokak 157/37. Lead toxicity resulted in increased level of the guaiacol peroxidase activity in both cultivars. Our results suggest that lead toxicity induced membrane damage in barley leaves, led to photosynthetic pigment loss and that guaiacol peroxidase activity may be critical for lead tolerance at early stage of seedling oxidative stress development. Keywords Ascorbate peroxidase . Glutathione reductase . Guaiacol peroxidase . Lead toxicity . Superoxide dismutase
Introduction Contamination of soils, sediments and water with toxic chemicals is one of the major problems for agricultural activities. The heavy metals, which could be included in the main pollutant category, may be found in the soil, water and also in the toxic gases formed by photochemical reactions in the atmosphere (Gratao et al. 2005; Afify and Abdel-Satar 2020). It has been reported that agricultural soils in many parts of the world are slightly to moderately contaminated by heavy metals such as Cd, Cu, Zn, Ni, Co, Cr, Pb and As (Huang et al. 2019). Some of these heavy metals such as Al, Cu, Zn, Ni and Co are essential elements for the growth and metabolism of plants. Cd, Cr, Pb and As, however, are not essential and they do not perform any physiological function in plants. Both heavy metal groups show potential toxic effects on the overall growth and metabolism of plants when present in high
* Ali Doğru [email protected] 1
Sakarya University Faculty of Arts and Science Department of Biology, Esentepe, 54187 Sakarya, Turkey
concentrations in soils. As a non-essential element, lead (Pb2+) is one of the most abundant toxic metals in soils (Yadav 2010). The toxic level of Pb in soil results from mining and smelting activities, gasoline, explosives, fertilizers and pesticides (Sharma and Dubey 2005; Steffan et al. 2018). Plants could easily absorb Pb and accumulate it in roots, stems, leaves,
Data Loading...
