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Modulation of exogenous selenium in cadmium‐induced changes in antioxidative metabolism, cadmium uptake, and photosynthetic performance in the 2 tobacco genotypes differing in cadmium tolerance
Author(s) -
Liu Wenxing,
Shang Shenghua,
Feng Xue,
Zhang Guoping,
Wu Feibo
Publication year - 2015
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.2760
Subject(s) - cadmium , superoxide dismutase , catalase , chemistry , peroxidase , selenium , glutathione reductase , photosynthesis , glutathione , antioxidant , stomatal conductance , malondialdehyde , reactive oxygen species , atpase , glutathione peroxidase , biochemistry , enzyme , organic chemistry
Abstract Hydroponic experiments were conducted using cadmium (Cd)–sensitive ( cv Guiyan 1) and Cd‐tolerant (Yunyan 2) tobacco cultivars to evaluate cultivar differences in response to Cd toxicity in the presence of selenium (Se). The results showed that addition of 3 µM Se in 50 µM Cd solution markedly reduced Cd accumulation in plants, alleviated Cd‐induced growth inhibition, and increased nitrogen and chlorophyll contents as well as photosynthetic performance (i.e., net photosynthetic rate, stomatal conductance, and transpiration rate). External Se dramatically depressed Cd‐induced O 2 •− , H 2 O 2 , and malondialdehyde accumulation, especially in the sensitive cultivar. Selenium significantly elevated Cd‐depressed activities of superoxide dismutase, peroxidase, catalase, ascorbate peroxidase, glutathione‐peroxidase, and glutathione reductase in the both cultivars after 7‐d treatments. Meanwhile, Se counteracted Cd‐induced alterations in certain nutrient elements; for example, it significantly increased Zn and Ca concentrations and reduced Mg concentration in both cultivars. Furthermore, Se significantly elevated Cd‐depressed H + ‐K + ‐adenosine triphosphatase (ATPase), Na + ‐K + ‐ATPase, and Ca 2+ ‐Mg 2+ ‐ATPase activities. The beneficial effect of Se under Cd stress may be related mainly to the increased ATPase activity and reduced Cd uptake and reactive oxygen species accumulation, thus reducing the negative consequences of oxidative stress caused by Cd toxicity. Environ Toxicol Chem 2015;34:92–99. © 2014 SETAC