Germinating Peanut (Arachis hypogaea L.) Seedlings Attenuated Selenite-Induced Toxicity by Activating the Antioxidant Enzymes and Mediating the Ascorbate–Glutathione Cycle

Abstract

Selenite can enhance the selenium nutrition level of crops, but excessive selenite may be toxic to plant growth. To elucidate the mechanisms underlying the role of selenite in production and detoxification of oxidative toxicity, peanut seedlings were developed with sodium selenite (0, 3, and 6 mg/L). The effects of selenite on antioxidant capacity, transcript levels of antioxidant enzyme genes, and enzyme activities in hypocotyl were investigated. The CuZn-SOD, GSH-Px, GST, and APX gene expression levels and their enzyme activities in selenite treatments were 1.0-3.6-fold of the control. Selenite also significantly increased the glutathione and ascorbate concentrations by mediating the ascorbate-glutathione cycle, and the selenite-induced hydrogen peroxide may act as a second messenger in the signaling pathways. This work has revealed a complex antioxidative response to selenite in peanut seedling. Understanding these mechanisms may help future research in increasing selenite tolerance and selenium accumulation in peanut and other crops.

2,4-D attenuates salinity-induced toxicity by mediating anatomical changes, antioxidant capacity and cation transporters in the roots of rice cultivars

“…In the present study, the application of 2,4 D enhanced the activation of antioxidant enzymes under saline stress conditions, which is in line with previous studies in which natural auxin and synthetic auxin (2,4-D) stimulated the activities of antioxidant enzymes, such as SOD, CAT, and APX in wheat, maize and other plants under abiotic stress conditions 65 – 67 . This may suggest that enhanced antioxidant capacity under combined stress conditions may be due to 2,4-D modification in the transcription of the genes that encode antioxidant enzymes.…”

“…GSH and AsA are directly oxidized by ROS, or indirectly oxidized via coupling reactions of the ascorbate–glutathione recycling pathway 67 , 70 . In this study, the GR activity significantly increased in the resistant cultivar compared to the sensitive one under saline stress and combined treatments, which correlates with the a higher accumulation of GSH in XS 134 cultivar compared with the ZJ 88 cultivar under the saline stress and combined treatments (Table 3 ).…”

“…In this study, the GR activity significantly increased in the resistant cultivar compared to the sensitive one under saline stress and combined treatments, which correlates with the a higher accumulation of GSH in XS 134 cultivar compared with the ZJ 88 cultivar under the saline stress and combined treatments (Table 3 ). Different authors have suggested that higher concentration of GSH stimulates AsA regeneration via the ascorbate−glutathione cycle under stress conditions 10 , 67 . This assumption is supported by the fact that the AsA accumulation was enhanced in cultivar XS 134 under saline and combined stress treatments compared with sensitive cultivar.…”

Identification and Allelopathy of Green Garlic (Allium sativum L.) Volatiles on Scavenging of Cucumber (Cucumis sativus L.) Reactive Oxygen Species

“…For the assay of antioxidant substances, 1.0 g of cucumber leaves were homogenized in 5 mL of 1% ( w / v ) saline buffer (1% ( w / v ) PVP, 1 mmol/L ethylenediaminetetraacetic acid (EDTA)). Homogenates were centrifuged at 11,000 g for 15 min at 4 °C and the supernatants were collected to check the content of ASA and GSH [39].…”

Bamboo Leaf Flavonoids Extracts Alleviate Oxidative Stress in HepG2 Cells via Naturally Modulating Reactive Oxygen Species Production and Nrf2‐Mediated Antioxidant Defense Responses

“…It is reported that living cells contain a large number of antioxidant enzymes and CAT and GSH‐Px production has been frequently employed to describe the cellular oxidative stress state (Wang et al., ). As shown in Figure D and 3E, cells with 24‐hr OA incubation obtained the lowest CAT and GSH‐Px production, showing the OA‐induced oxidative damage ( P < 0.05).…”