Salinity stress occurs due to the accumulation of high levels of salts in soil, which ultimately leads to the impairment of plant growth and crop loss. Stress tolerance-inducing compounds have a remarkable ability to improve growth and minimize the effects of salinity stress without negatively affecting the environment by controlling the physiological and molecular activities in plants. Two pot experiments were carried out in 2017 and 2018 to study the influence of salicylic acid (1 mM), yeast extract (6 g L−1), and proline (10 mM) on the physiological and biochemical parameters of sweet pepper plants under saline conditions (2000 and 4000 ppm). The results showed that salt stress led to decreasing the chlorophyll content, relative water content, and fruit yields, whereas electrolyte leakage, malondialdehyde (MDA), proline concentration, reactive oxygen species (ROS), and the activities of antioxidant enzymes increased in salt-stressed plants. The application of salicylic acid (1 mM), yeast extract (6 g L−1), and proline (10 mM) markedly improved the physiological characteristics and fruit yields of salt-stressed plants compared with untreated stressed plants. A significant reduction in electrolyte leakage, MDA, and ROS was also recorded for all treatments. In conclusion, our results reveal the important role of proline, SA, and yeast extracts in enhancing sweet pepper growth and tolerance to salinity stress via modulation of the physiological parameters and antioxidants machinery. Interestingly, proline proved to be the best treatment.

https://www.mdpi.com/2073-4395/10/1/26/pdf

Treatment of Sweet Pepper with Stress Tolerance-Inducing Compounds Alleviates Salinity Stress Oxidative Damage by Mediating the Physio-Biochemical Activities and Antioxidant Systems

Nanoparticle-based amelioration of drought stress and cadmium toxicity in rice via triggering the stress responsive genetic mechanisms and nutrient acquisition.

Zero-dimensional sulfur nanomaterials: Synthesis, modifications and applications

Nanofertilizers for agricultural and environmental sustainability

Green synthesis of sulfur nanoparticles using Ocimum basilicum leaves and its prospective effect on manganese-stressed Helianthus annuus (L.) seedlings

Salinity is a critical issue impairing the growth and productivity of most crop species through the mediated ionic and osmotic imbalances. As a way forward, the current study was tailored to elucidate the capacity of sulfur nanoparticles (SNPs) to amend salinity consequences on growth and physio-biochemical attributes of wheat. In a controlled experiment, wheat seeds were primed for 12 h with either 100 μM SNPs or deionized water then sown in plastic pots containing 5 kg clay-sand mixture (2:1 w/w). A week later, pots received NaCl (100 or 200 mM) as a sole treatment or in combination with SNPs and after three weeks the data of morph-bio-physiological traits were recorded. Salinity decreased growth rate, pigmentation, protein, amino acids, cysteine, ascorbate, flavonoids and phenolics content in wheat leaves. Plants pre-treated with 100 μM SNPs showed improved growth rate, pigmentation, nitrogen metabolism as well as non-enzymatic antioxidant contents as compared with salinized treatments. Neither salt nor SNP treatments affected photosynthetic performance rate (Fv/fm), however both treatments induced glutathione content. SNP treatment retrieved the undue excessive activities of catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), superoxide dismutase (SOD) and polyphenol oxidase (PPO) besides the increased level of proline caused by salt stress. Likewise, 100 μM SNPs rebalanced the declined nitrogen, phosphorus and potassium contents and decreased sodium uptake caused by salinity. On the whole, priming with 100 μM SNPs improved photosynthetic pigments, nitrogen metabolism, antioxidant status and ionic relations contributing to the enhancement of growth attributes in wheat under salinity.

Sulfur nanoparticles mediated improvement of salt tolerance in wheat relates to decreasing oxidative stress and regulating metabolic activity.

Increased urbanization detrimentally affects crop plants. Heavy metals pollution sharply threatens food security. However, greenly synthesized nanoparticles were recently proposed as growth bioregulators. To investigate the evolved mechanisms by which sulfur nanoparticles (SNPs) could improve cellular defense against manganese toxicity, the present experiment was applied on Helianthus annuus (L.) seedlings. The experimental design was based on priming of sunflower seeds for 18 h in different (12.5–200 μM) SNPs, while 100 mM manganese sulfate (MnSO4) was implemented as irrigation treatment. The 14-day-old seedlings manifested Mn noxiousness and oxidative stress indications such as increased reactive oxygen species (O2·− and H2O2) and lipid peroxidation. Manganese exposure severely lowered the activity of some antioxidant enzymes like superoxide dismutase (SOD) and catalase (CAT), while induced ascorbate peroxidase (APX), guaiacol peroxidase (POX), polyphenol oxidase (PPO), and glutathione reductase (GR) activities. An evident decline in the pool of antioxidant compounds, such as ascorbic acid (ASA), glutathione (GSH), and total flavonoids content (TFC), was attained with Mn stress. Priming with SNPs significantly stimulated CAT and SOD activities and enhanced the antioxidant compounds (ASA, TFC, and total phenolic compounds) level in Mn-stressed seedlings. Consequently, SNPs caused a significant decrease in O2·−, H2O2, and lipid peroxidation and their oxidative damage. However, a significant reduction in GSH was detected with SNPs that might be consumed and incorporated into biosynthesis of other chelating ligands. Therefore, SNPs manifested a vital role in Mn detoxification through counterbalancing oxidative damage and elevating the antioxidant defense machinery.

Seed Priming with Greenly Synthesized Sulfur Nanoparticles Enhances Antioxidative Defense Machinery and Restricts Oxidative Injury Under Manganese Stress in Helianthus annuus (L.) Seedlings

T HE EFFECT of CuSO4 stress on some growth parameters and some metabolites in 14-day-old Vicia faba seedlings was studied. Irrigation with 150 mM CuSO4 resulted in remarkable reduction in root length, shoot height, fresh and dry weights of root and shoot, leaf area and photosynthetic pigments (Chl a, Chl b and carotenoids), while it raised Chl a/b ratio. Total soluble carbohydrates and protein contents were significantly depleted under Cu treatment. The ameliorative role of seed priming with different concentrations of yeast extract (25, 50, or 100 %), IAA (0.1, 0.3, 0.5 mM), or the green-synthesized Nano zinc oxide with average size 61 (nm) prepared from leaf extract of Coriandrum sativum (10, 50, 100 ppm) for different periods (6 and10h for yeast and IAA, 3 and 6h for Nano ZnO were studied. Results revealed that seed priming with 50% yeast or 0.1 mM IAA for 10h showed a remarkable increase in the measured growth criteria, chla, chl b, soluble carbohydrates and proteins but diminished chl a/b ratio compared with the Cu stress treatment. Seed priming with 100 ppm Nano ZnO for 6 h exhibited the most effective treatment in mitigating the harmful effects of Cu stress on growth criteria, Chla, Chl b, soluble carbohydrates and proteins.

https://ejbo.journals.ekb.eg/article_3618_08a95b5f13649755dada85a19b43ba56.pdf

Ameliorative effect of Yeast Extract, IAA and Green-synthesized Nano Zinc Oxide on the Growth of Cu-stressed Vicia faba Seedlings

This work aims at studying the possibility of the safe application of sewage sludge (SS) biosolids as low-cost soil fertilizer to improve soil properties and crop productivity. In the present study, Sorghum bicolor was cultivated in soil amended with SS (0, 10, 20, 30, 40, 50 g/kg) to investigate its impact on soil quality and sorghum yield. Applying SS rates significantly increased growth parameters, total biomass, and absolute growth rate compared to the plants grown in the non-amended (control) soils, whereas 30 g/kg SS had the highest values and was considered as a recommended dose. The induced growth at 30 g/kg SS was accompanied with a significant increment in metals contents in roots, stems, and leaves, and had normal safe limits in the produced grains. After harvesting, the soil quality was improved, and its pH value decreased from 8.4 to 7.7, offering an increased availability of micronutrients. Furthermore, amending S. bicolor with 30 g/kg SS elevated bioaccumulation factor (BF) values over 1 for Cu, Ni, Zn, and Cr compared to the control, indicating its remediating capability with values of 2.32, 1.97, 1.42, and 1.15, respectively. Alternatively, at the recommended SS dose, the upper uptake of Pb significantly increased in the leaves having translocation factor (TF) value of 1.18. The current work proposes that soil amendment with 30 g/kg SS is recommended to enhance soil fertility and plant yield, with no health risks when eating the produced grains, with potential heavy metal phytoextracting by S. bicolor.

/pdf/monitored-sewage-sludge-application-improves-soil-quality-44b3quywxi.pdf

Gehad A. Ragab

Papers

Green synthesis of sulfur nanoparticles using Ocimum basilicum leaves and its prospective effect on manganese-stressed Helianthus annuus (L.) seedlings

Sulfur nanoparticles mediated improvement of salt tolerance in wheat relates to decreasing oxidative stress and regulating metabolic activity.

Seed Priming with Greenly Synthesized Sulfur Nanoparticles Enhances Antioxidative Defense Machinery and Restricts Oxidative Injury Under Manganese Stress in Helianthus annuus (L.) Seedlings

Ameliorative effect of Yeast Extract, IAA and Green-synthesized Nano Zinc Oxide on the Growth of Cu-stressed Vicia faba Seedlings

Monitored Sewage Sludge Application Improves Soil Quality, Enhances Plant Growth, and Provides Evidence for Metal Remediation by Sorghum bicolor L.