Modulation of Physiological Stress Response of Triticum aestivum L. to Glyphosate by Brassinosteroid Application

Abstract

The potential of brassinosteroids to modulate the physiological responses of winter wheat (Triticum aestivum L.) to herbicide stress was evaluated. Young winter wheat seedlings were treated with 24-epibrassinolide (EBL) and 24 h later were sprayed with glyphosate. The physiological responses of treated plants were assessed 14 days after herbicide application. Wheat growth was noticeably inhibited by glyphosate. The herbicide application significantly increased the content of the stress markers proline and malondialdehyde (MDA) evidencing oxidative damage. The content of phenolic compounds was decreased in the herbicide-treated plants. Slight activation of superoxide dismutase (SOD) and catalase (CAT) and considerable increase of glutathione reductase (GR) and guaiacol peroxidase (POX) activities were found. Increased POX and glutathione S-transferase (GST) activities were anticipated to be involved in herbicide detoxification. Conjugation with glutathione in herbicide-treated plants could explain the reduction of thiols suggesting unbalanced redox state. EBL application did not alter the plant growth but a moderate activation of antioxidant defense (POX, GR, and CAT activities and phenolic levels) and detoxifying enzyme GST was observed. The hormonal priming provoked a slight decrease in MDA and proline levels. The results demonstrate that EBL-pretreatment partly restored shoot growth and has a potential to mitigate the oxidative damages in glyphosate-treated plants through activation of the enzymatic antioxidant defense and increase of the phenolic compounds.

Enhancement of the Expression of ZmBZR1 and ZmBES1 Regulatory Genes and Antioxidant Defense Genes Triggers Water Stress Mitigation in Maize (Zea mays L.) Plants Treated with 24-Epibrassinolide in Combination with Spermine

“…Moreover, a concomitant decrease in H 2 O 2 burst was also detected in treated plants. This observation is corroborated by other studies, which state that EBL is crucial in altering the performance of antioxidant enzymes, giving cells a better chance of surviving damage brought by stressful conditions [23][24][25][26]. In this study, it was shown that the expression of genes encoding ZmBZR1 and ZmBES1 transcription factors in water-stressed EBL-treated plants was increased, and there was also a concomitant decrease in H 2 O 2 level in plants, indicating that these genes may have a function in ROS detoxification.…”

“…Plants with defects in BR biosynthesis or signaling, in particular, have a dwarf phenotype, indicating that BR is important for normal plant growth and development [21]. Different studies have shown that the exogenous application of BRs increases the tolerance to abiotic stresses by stimulating the enzymatic and non-enzymatic antioxidant defense system [22][23][24][25][26][27].…”

Synergistic Effects of Salicylic Acid and Melatonin on Modulating Ion Homeostasis in Salt-Stressed Wheat (Triticum aestivum L.) Plants by Enhancing Root H+-Pump Activity

“…In addition, salinity causes oxidative stress and increases the generation of ROS, which are highly cytotoxic and can react with essential biomolecules including lipids, proteins, and nucleic acids, resulting in lipid peroxidation, protein denaturation, and DNA mutation, respectively [ 3 , 6 ]. Enhancing the activity of plant antioxidant enzymes (superoxide dismutase, catalase, peroxidase, and enzymes involved in the ascorbate–glutathione cycle) is very important to counter oxidative stress [ 13 , 14 , 15 ].…”

Antioxidant Machinery and Glyoxalase System Regulation Confers Salt Stress Tolerance to Wheat (Triticum aestivum L.) Plants Treated with Melatonin and Salicylic Acid

“…The enzymatic system includes superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (POD), ascorbate peroxidase (APX), glutathione peroxidase (GPX), glutathione reductase (GR), glutathione S-transferase (GST), monodehydroascorbate reductase (MDHAR), and dehydroascorbate reductase (DHAR), while the non-enzymatic antioxidants include glutathione (GSH), ascorbic acid (AsA), phenolic compounds, flavonoids, carotenoids, α-tocopherol, etc. (Singh et al 2019;Shen et al 2021;Shopova et al 2021). Salt stress also stimulates methylglyoxal (MG) production.…”