Effects of selenium and sulfur on antioxidants and physiological parameters of garlic plants during senescence

Abstract

A hydroponic study was conducted to determine the effects of selenium (Se: 0μmol• L −1 , 3μmol• L −1 , 6μmol• L −1 ) on senescence-related oxidative stress in garlic plants grown under two sulfur (S) levels. We evaluated the yields of plants harvested at 160 and 200 days after sowing. Plants grown under a low-Se dose (0.3 μmol•L −1 ) at low S level showed higher yields (12.0% increase in fresh weight yield, 13.7% increase in dry weight yield) than those of controls, despite a decrease in chlorophyll concentration. Compared with control plants, the Se-treated plants showed lower levels of lipid peroxidation. The Se-treated plants also showed higher activities of glutathione peroxidase and catalase, but lower superoxide dismutase activities. Changes in Fv/Fm values and proline contents were affected more strongly by S than by Se. On the basis of our results, we can conclude that Se plays a key role in the antioxidant systems in garlic seedlings. It delays senescence by alleviating the peroxide stress, but it can be toxic at high levels. A high S level may increase tolerance to high Se concentrations through reducing Se accumulation in plants.

Selenium biofortification on garlic growth and other nutrients accumulation

“…The Se doses tested were 1.0 and 0.9 mg kg -1 of soil, respectively. The growth-promoting effect of Se may be attributable to its antioxidant properties (Cheng et al, 2016). The negative or positive effect of Se over the plant growth depends on its concentration (Fargasova, 2004).…”

“…Additionally, Se reduces the rate of protein synthesis because the substitution of SeMet for Met is less effective as a substrate for peptide bond formation during translocation (Eustice et al, 1981). On the other hand, the formation of Se-amino acids increases the ethylene production (Cheng et al, 2016). This phytohormone produces changes in the membrane lipid composition and increases membrane permeability that could affect the plant tissues (Xue et al, 2001).…”

“…Although Se-enriched garlic is an attractive option to naturally increase Se intake by humans, there are few studies on the uptake and accumulation during the growth of garlic plant (Poldma et al, 2011;Ogra et al, 2015;Cheng et al, 2016). Additionally, the application of Se can improve plant quality and yield, given that, Se has an antioxidative effect on plants which depends on Se doses (Zhao et al, 2013).…”

Physiological, biochemical, and ultrastructural characterization of selenium toxicity in cowpea plants

“…The decrease in H 2 O 2 concentrations caused by the activity of other enzymes (e.g., CAT and APX) may have provided an environment where there was no stimulus for SOD synthesis. Some studies have already shown that Se negatively impacts SOD activity in plants Xue and Hartikainen, 2000;Cheng et al, 2016;Reis et al, 2018).…”

Selenium-sulphur effects on the chemical composition of alfalfa (Medicago sativaL. cv. Verko)

“…In the present study, a 3 g Se ha −1 solution of selenate and 3 g S ha −1 sulphate as well as a combination of both elements clearly caused to stimulate the biomass of alfalfa plant. The application of Se in plants increases biomass accumulation (Cheng et al, 2016) or yield (Põldma et al, 2013). Growth-promoting Se effects have been reported in lettuce (Xue et al, 2001), ryegrass (Hartikainen et al, 1997;Hartikainen & Xue, 1999), and soybean (Djanaguiraman et al, 2005).…”