Physiological responses of peanut seedlings to exposure to low or high cadmium concentration and the alleviating effect of exogenous nitric oxide to high cadmium concentration stress

Abstract

The physiological responses of peanut seedlings exposed to low (5 µM) or high (200 µM) cadmium (Cd) concentration and the ability of sodium nitroprusside (SNP, a donor of NO) to reverse the harmful effects of Cd on peanut (Arachis hypogaea L.) were studied. Changes in plant growth parameters, chlorophyll content, antioxidant system, nutrient contents and Cd accumulation were investigated. The results showed that SNP and 5 µM Cd improved plant growth and chlorophyll content. Furthermore, antioxidative system was up-regulated, and as a result, the production rate of superoxide radical (O₂^•−) was reduced. Moreover, the absorption of nutrient elements was not impacted, and Cd toxicity was not observed. However, 200 µM Cd had negative effects on the above measured parameters and dramatically increased the accumulation of Cd in all the plant organs. In the 200 µM Cd treatment, addition of 250 µM SNP stimulated plant growth and increased chlorophyll content. It also enhanced the regulation of antioxidative system and reduced the production rate of O₂^•− and malondialdehyde (MDA) content. Besides, SNP supply enhanced the absorption of nutrient elements and restrained the absorption and transport of Cd.

Keywords:

• Peanut (Arachis hypogaea L.)
• cadmium
• SNP
• nitric oxide
• antioxidative systems
• ion accumulation
• nutrient elements

Acknowledgements

Special acknowledgements are given to the editors and reviewers.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was financially supported by the Shandong Provincial Natural Science Foundation of China (ZR2017MD010), Taishan Scholars at Seed Industry Talent Project-Shandong Province Seed Industry Project, the Major Science and Technology Innovation Projects of Shandong Province (2017CXGC0301) and the Primary Research & Development Plan of Shandong Province (2016CYJS05A02).