Table 2.

Evidence for Se-induced oxidative stress in plants.

Plant Species	Form and Concentration of Se	Indicators of Oxidative Stress and Changes in Antioxidant Enzymes Activities under Se Exposure	Reference
Arabidopsis thaliana	SeO32–; 50 or 100 μM	Distinct oxidative stress. Nitrosative modifications. Callose accumulation. Pectin accumulation.	[26]
Pisum sativum	SeO32–; 50 or 100 μM	Increased H2O2 concentration in leaves and roots. Increased content of thiobarbituric acid reactive substances (TBARS). Altered GSH content, APX and CAT activities. Increased nitric oxide level in shoot and root. Nitric oxide-induced nitrooxidative stress by increasing peroxynitrite formation, as well as tyrosine nitration.	[30]
Brassica rapa	SeO32–; 0.03–0.46 mM	Increased endogenous total ROS, O2•−, and enhanced lipid peroxidation. Loss of plasma membrane integrity in the roots.	[157]
Triticum aestivum	SeO42–; 100 μM	Altered carbohydrates (soluble and starch) level. AsA and GSH contents were modified. Suppressed activities of SOD, APX, and GR. Higher generation of ROS. Augmented lipid peroxidation. Repressed PSII and PSI system activities. Modified redox status connected with Mn(II)/Mn(III), and semiquinone/quinone ratios.	[120]
A. thaliana	SeO42–; 20 and 40 μM	Decreased NO content. Increased H2O2 content. Reduced cell viability.	[121]
Vicia faba	SeO42–; 6 μM	Elevated lipid peroxidation and total -SH (T-SH) content. Increased GPX activity. Decreased guaiacol peroxidase (GPOX) activity. Increased O2•− production in the roots. Cell membrane injury and reduced cell viability.	[158]
Stanleya pinnata	SeO42–; 40 and 80 μM	Oxidized proteins. Malformed or misfolded selenoproteins.	[159]
Ulva sp.	SeO42–; 100 μM	Increased accumulation of H2O2. The activity of antioxidant enzymes such as SOD, CAT increased. Antioxidant metabolites including phenols, flavonoids, carotenoids, and gallic acid increased.	[123]
A. thaliana	SeO42–; 20 μM	The cad2-1 mutant was recognized with a flawed GSH synthetic pathway that showed decreased root length, in contrast to the wild type. In the apr2-1 mutant, GSH depletion and ROS accretion were prominent.	[160]
Hordeum vulgare	SeO42–; 4, 8 and 16 ppm	Increased membrane lipid peroxidation. Higher proline accumulation. Stimulated CAT, APX, GR, and glutathione-S-transferase (GST) activities.	[126]
Stanleya albescens	SeO42–; 20 μM	Increased O2•− and H2O2 levels. Reduced AsA and GSH content. Declined radical-scavenging capacity.	[127]
A. thaliana	SeO42–; 50 mM	Decreased GSH level.	[161]