Positive Interaction of Selenium Nanoparticles and Olive Solid Waste on Vanadium-Stressed Soybean Plant

Abstract

The purpose of the current study was to determine the possible improvement in soybean plants’ tolerance against vanadium-induced stress in response to the application of olive solid waste (OSW) and selenium nanoparticles (Se-NPs), by assessing metabolites and plant defense systems. Drawing upon this aim, a pot experiment was performed where the soybean plants were grown with a fertilization treatment (including, control, OSW, Se-NPs, and Se-NPs + OSW) under vanadium stress (including non-stress and 350 mg sodium orthovanadate per kg of soil). Enhancement of hydrogen peroxide (H2O2) and malondialdehyde (MDA) accumulation in vanadium-stressed plants confirmed the oxidative damage in unfertilized plants. Results indicated the positive effects of the combined treatment (Se-NPs + OSW) in improving the plant stress tolerance by causing a balance in the produced ROS and detoxified ROS in the plant. It was mainly stimulated through the improvement of the photosynthetic parameters, anthocyanin metabolism pathway, phenylpropanoid pathway, non-enzymatic antioxidant metabolites (tocopherols, malondialdehyde, polyphenols, and flavonoids), antioxidant enzymes, and biochemical components involved in the ASC/GSH cycle (ascorbate, ascorbate peroxidase, dehydroascorbate reductase, monodehydroascorbate reductase, glutathione, glutathione reductase, and glutathione peroxidase), and antioxidant direct scavenging enzymes (peroxidase, catalase, and superoxide dismutase), which finally resulted in higher plant biomass. In conclusion, the simultaneous application of OSW and Se-NPs treatments provided a reliable protection for soybean plants in vanadium-contaminated soils through the activation of antioxidant and non-antioxidant defense mechanisms.

Chromium(VI) Toxicity and Active Tolerance Mechanisms of Wheat Plant Treated with Plant Growth-Promoting Actinobacteria and Olive Solid Waste

“…55 In addition, the susceptibility of the components of the ASC/ GSH cycle and other antioxidant pathways to oxidative stress should be considered because it can thereupon influence their antioxidant potential under stress, despite their defensive function in preserving the cellular components from oxidative damage. 12,55 We also focused on antioxidant molecules from different antioxidant pathways to debate whether antioxidant capacity in fertilized plants can be improved under chromium stress. Our findings provide more clearance for the improvement of the levels of the main antioxidant molecules, including vitamins (tocopherols), polyphenols, flavonoids, and TAC, in plants treated with PGPB and OSW treatments (Figure 4A).…”

“…The estimation of ascorbate peroxidase (APX) and glutathione reductase (GR) activities was fully described by Sohel Murshed et al The reduction in NADPH absorption at 340 nm was recorded to determine glutathione peroxidase (GPX) activity . Reduced glutathione (GSH), reduced ascorbate (ASC), and phytochelatins levels were assessed by high-performance liquid chromatography (HPLC). , Glutathione S-transferase (GST) activity was determined using 1-chloro-2,4-dinitro-benzene as the substrate, based on the method of Habig et al…”

“…10,11 On the other hand, another main concern in agricultural sustainability has been the underscore on the recovery and recycling of food byproducts and wastes. 12 Producing organic fertilizers from olive solid waste (OSW), as a source of optimum nutritive value compounds, has been the subject of intense attention within the scientific community. 13 OSW, generated by the olive oil manufacturing process, is known for its positive effects on plants, especially under heavy metal stress.…”

“…13 OSW, generated by the olive oil manufacturing process, is known for its positive effects on plants, especially under heavy metal stress. 12 It has previously been reported that OSW not only has antimicrobial and antiviral capability 14 but also contributes to enrich the organic matter content (e.g., fiber, lignin, uronic acids, and polyphenolic compounds; >1 mg g −1 ), N (>5 mg g −1 ), P (>3 mg g −1 ), and K (>11 mg g −1 ). 12,15 Despite the previous findings summarized above, there has been little discussion about the synergic effects of olive waste and beneficial bacteria in soils on the metabolites and biochemical composition of plants, especially with heavy metal pollutants.…”

“…12 It has previously been reported that OSW not only has antimicrobial and antiviral capability 14 but also contributes to enrich the organic matter content (e.g., fiber, lignin, uronic acids, and polyphenolic compounds; >1 mg g −1 ), N (>5 mg g −1 ), P (>3 mg g −1 ), and K (>11 mg g −1 ). 12,15 Despite the previous findings summarized above, there has been little discussion about the synergic effects of olive waste and beneficial bacteria in soils on the metabolites and biochemical composition of plants, especially with heavy metal pollutants. The present study aimed to address the following questions (i) whether oxidative stress caused by chromium toxicity can be alleviated in wheat (Triticum aestivum) treated with a consortium of plant growth-promoting Actinobacteria or OSW?, (ii) whether the improvement of metabolic parameters and biochemical compounds of plants in the simultaneous application of beneficial Actinobacteria and olive waste is more pronounced than their individual applications.…”