Modulation of Antioxidant Machinery and the Methylglyoxal Detoxification System in Selenium-Supplemented Brassica napus Seedlings Confers Tolerance to High Temperature Stress

Abstract

We investigated the protective role of selenium (Se) in minimizing high temperature-induced damages to rapeseed (Brassica napus L. cv. BINA Sarisha 3) seedlings. Ten-day-old seedlings which had been supplemented with Se (25 μM Na2SeO4) or not were grown separately under control temperature (25 °C) or high temperature (38 °C) for a period of 24 or 48 h in nutrient solution. Heat stress caused decrease in chlorophyll and leaf relative water content (RWC) and increased malondialdehyde (MDA), hydrogen peroxide (H2O2), proline (Pro), and methylglyoxal (MG) contents. Ascorbate (AsA) content decreased at any duration of heat treatment. The content of reduced glutathione (GSH) increased only at 24 h of stress, while glutathione disulfide (GSSG) markedly increased at both duration of heat exposure with associated decrease in GSH/GSSG ratio. Upon heat treatment the activities of ascorbate peroxidase (APX), glutathione S-transferase (GST) and glyoxalase I (Gly I) were increased, while the activities of monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), and catalase (CAT) were decreased. The activities of glutathione reductase (GR) and glutathione peroxidase (GPX) remained unchanged under heat stress. However, heat-treated seedlings which were supplemented with Se significantly decreased the lipid peroxidation, H2O2, and MG content and enhanced the content of chlorophyll, Pro, RWC, AsA, and GSH as well as the GSH/GSSG ratio. Selenium supplemented heat-treated seedlings also showed enhanced activities of MDHAR, DHAR, GR, GPX, CAT, Gly I, and Gly II as compared to heat-treated seedlings without Se supplementation. This study concludes that exogenous Se application confers heat stress tolerance in rapeseed seedlings by upregulating the antioxidant defense mechanism and methylglyoxal detoxification system.

Involvement of l-Cysteine Desulfhydrase and Hydrogen Sulfide in Glutathione-Induced Tolerance to Salinity by Accelerating Ascorbate-Glutathione Cycle and Glyoxalase System in Capsicum

“…Glyoxalase I (Gly I) activity was quantified employing the protocol outlined by Hasanuzzaman et al [ 66 ]. A solution of 100 mmol L −1 potassium-phosphate buffer at pH 7.0, comprising 15 mmol L −1 magnesium sulfate, 1.7 mmol L −1 GSH, and 3.5 mmol L −1 MG, was reacted with the enzyme assay solution.…”

“…Optical density was read at 240 nm. For the quantification of glyoxalase II (Gly II) activity, the protocol delineated by Hasanuzzaman et al [ 66 ] was adopted. A solution containing 100 mmol L −1 Tris-HCl buffer (pH 7.2), 0.2 mmol L −1 DTNB, and 1.0 mmol L −1 S - d -lactoylglutathione (SLG) was poured into the enzyme assay solution.…”

Selenium and Human Health: Witnessing a Copernican Revolution?

“…The adaptive stress response hypothesis with respect to Se was further challenged by Vinceti et al, who have summarized some more studies and presented some more insights into this intriguing issue, as discussed and addressed below [168]. Firstly, it should be noted, that prooxidant activity of Se was shown to cause upregulation of Se-independent antioxidant enzymes, such as catalase and superoxide dismutase, in different biological systems, and these observations come from plants [169,170], yeast [171], fish [172][173][174][175][176] and, importantly, human cancer cell lines [50,177]. Secondly, such adaptive stress response, specifically with respect to Se-containing enzymes, is also well known to occur following acute and chronic injury 29 human studies [178][179][180][181][182][183][184][185][186][187][188][189][190][191][192][193][194][195][196] showing that selenoproteins (including GPx and Sepp1) are upregulated in the response to oxidative stress from their baseline levels without any change in Se supply and availability, i.e.…”

Exogenous application of NaBiF4 nanoparticle affects wheat root development

“…The activities of SOD, CAT, and POD activity of wheat root was measured as described previously [29,30].4 day after germination, the seedling wheat plants were move to 50 μM NaBiF 4 and BiF 3 nanoparticles water solution for 3 days. About 100 mg of mixed material were harvested and ground in liquid nitrogen to a fine powder and then homogenized in 5 ml 10 mM PBS (pH 7.0) containing 1% PVP (w/v), 1 mM PMSF, 0.1% Triton-X100 (w/v) and 0.1 mM EDTA.…”