Comparison of selenite and selenate in alleviation of drought stress in Nicotiana tabacum L. (January 2022)

• Record Type: Journal Article
• Authors: Han, Dan; Tu, Shuxin; Dai, Zhihua; Huang, Wuxing; Jia, Wei; Xu, Zicheng; Shao, Huifang
• Is Part Of: Chemosphere. Volume 287:Part 2(2022)
• Publication Date: 2022-01
• Subjects: Sodium selenate -- Sodium selenite -- Antioxidant enzymes -- Gene expression -- Drought stress; Se selenium -- Na2SeO4 sodium selenate -- Na2SeO3 sodium selenite -- SOD superoxide dismutase -- POD peroxidase -- CAT catalase -- MDA malondialdehyde -- RWC relative water content -- Na sodium -- Mg magnesium -- Ca calcium -- PEG Polyethylene glycol -- CK control -- SEMs scanning electron micrographs -- ROS reactive oxygen species -- Pn net photosynthetic -- Gs stomatal conductance -- Tr transpiration rate -- Ci intercellular CO2 concentration; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2021.132136
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Exogenous selenium (Se) improves the tolerance of plants to abiotic stress. However, the effects and mechanisms of different Se species on drought stress alleviation are poorly understood. This study aims to evaluate and compare the different effects and mechanisms of sodium selenate (Na2 SeO4 ) and sodium selenite (Na2 SeO3 ) on the growth, photosynthesis, antioxidant system, osmotic substances and stress-responsive gene expression of Nicotiana tabacum L. under drought stress. The results revealed that drought stress could significantly inhibit growth, whereas both Na2 SeO4 and Na2 SeO3 could significantly facilitate the growth of N. tabacum under drought stress. However, compared to Na2 SeO3, Se application as Na2 SeO4 induced a significant increase in the root tip number and number of bifurcations under drought stress. Furthermore, both Na2 SeO4 and Na2 SeO3 displayed higher levels of photosynthetic pigments, better photosynthesis, and higher concentrations of osmotic substances, antioxidant enzymes, and stress-responsive gene ( NtCDPK2, NtP5CS, NtAREB and NtLEA5 ) expression than drought stress alone. However, the application of Na2 SeO4 showed higher expression levels of the NtP5CS and NtAREB genes than Na2 SeO3. Both Na2 SeO4 and Na2 SeO3 alleviated many of the deleterious effects of drought in leaves, which was achieved by reducing stress-induced lipid peroxidation (MDA) and H2 O2 content by enhancing the activity of antioxidant enzymes, while Na2 SeO4 application showed lower H2 O2 and MDA content than Na2 SeO3 application. Overall, the results confirm the positive effects of Se application, especially Na2 SeO4 application, which is markedly superior to Na2 SeO3 in the role of resistance towards abiotic stress in N. tabacum . Graphical abstract: Image 1 Highlights: Both Na2 SeO4 and Na2 SeO3 could significantly facilitate plant growth. Na2 SeO4 induced a significant increase in the root tip number and number of bifurcations compared to Na2 SeO3 . Se applied in the form of Na2 SeO4 showed higher expression levels of the NtCDPK2 and NtAREB genes than Na2 SeO3 . Na2 SeO4 application lowered H2 O2 and MDA content compared to Na2 SeO3 . Na2 SeO4 was markedly superior to Na2 SeO3 in the role of resistance towards abiotic stress in N. tabacum.