Induction of resilience strategies against biochemical deteriorations prompted by severe cadmium stress in sunflower plant when Trichoderma and bacterial inoculation were used as biofertilizers

BackgroundCadmium (Cd) is a highly toxic heavy metal. Its emission is suspected to be further increased due to the dramatic application of ash to agricultural soils and newly reclaimed ones. Thereby, Cd stress encountered by plants will exacerbate. Acute and chronic exposure to Cd can upset plant growth and development and ultimately causes plant death. Microorganisms as agriculturally important biofertilizers have constantly been arising as eco-friendly practices owing to their ability to built-in durability and adaptability mechanisms of plants. However, applying microbes as a biofertilizer agent necessitates the elucidation of the different mechanisms of microbe protection and stabilization of plants against toxic elements in the soil. A greenhouse experiment was performed using Trichoderma harzianum and plant growth-promoting (PGP) bacteria (Azotobacter chroococcum and Bacillus subtilis) individually and integrally to differentiate their potentiality in underpinning various resilience mechanisms versus various Cd levels (0, 50, 100, and 150 mg/kg of soil). Microorganisms were analyzed for Cd tolerance and biosorption capacity, indoleacetic acid production, and phosphate and potassium solubilization in vitro. Plant growth parameters, water relations, physiological and biochemical analysis, stress markers and membrane damage traits, and nutritional composition were estimated.ResultsUnequivocal inversion from a state of downregulation to upregulation was distinct under microbial inoculations. Inoculating soil with T. harzianum and PGPB markedly enhanced the plant parameters under Cd stress (150 mg/kg) compared with control plants by 4.9% and 13.9%, 5.6% and 11.1%, 55.6% and 5.7%, and 9.1% and 4.6% for plant fresh weight, dry weight, net assimilation rate, and transpiration rate, respectively; by 2.3% and 34.9%, 26.3% and 69.0%, 26.3% and 232.4%, 135.3% and 446.2%, 500% and 95.6%, and 60% and 300% for some metabolites such as starch, amino acids, phenolics, flavonoids, anthocyanin, and proline, respectively; by 134.0% and 604.6% for antioxidants including reduced glutathione; and by 64.8% and 91.2%, 21.9% and 72.7%, and 76.7% and 166.7% for enzymes activity including ascorbate peroxidase, glutathione peroxidase, and phenylalanine ammonia-lyase, respectively. Whereas a hampering effect mediated by PGP bacterial inoculation was registered on levels of superoxide anion, hydroxyl radical, electrolyte leakage, and polyphenol oxidase activity, with a decrease of 0.53%, 14.12%, 2.70%, and 5.70%, respectively, under a highest Cd level (150 mg/kg) compared with control plants. The available soil and plant Cd concentrations were decreased by 11.5% and 47.5%, and 3.8% and 45.0% with T. harzianum and PGP bacterial inoculation, respectively, compared with non-inoculated Cd-stressed plants. Whereas, non-significant alternation in antioxidant capacity of sunflower mediated by T. harzianum action even with elevated soil Cd concentrations indicates stable oxidative status. The uptake of nutrients, viz., K, Ca, Mg, Fe, nitrate, and phosphorus, was interestingly increased (34.0, 4.4, 3.3, 9.2, 30.0, and 1.0 mg/g dry weight, respectively) owing to the synergic inoculation in the presence of 150 mg of Cd/kg.ConclusionsHowever, strategies of microbe-induced resilience are largely exclusive and divergent. Biofertilizing potential of T. harzianum showed that, owing to its Cd biosorption capability, a resilience strategy was induced via reducing Cd bioavailability to be in the range that turned its effect from toxicity to essentiality posing well-known low-dose stimulation phenomena (hormetic effect), whereas using Azotobacter chroococcum and Bacillus subtilis, owing to their PGP traits, manifested a resilience strategy by neutralizing the potential side effects of Cd toxicity. The synergistic use of fungi and bacteria proved the highest efficiency in imparting sunflower adaptability under Cd stress

Impact of sewage water irrigation on Datura innoxia grown in sandy loam soil

Abstract Background A potential solution for recycling and reusing the massively produced sewage water (SW) is to irrigate certain plants instead of highly cost recycling treatment. Although the extensive and irrational application of SW may cause environmental pollution thus, continual monitoring of the redox status of the receiver plant and the feedback on its growth under application becomes an emergent instance. The impact of SW, along with well water (WW) irrigation of medicinal plant, Datura innoxia, was monitored by some physio-biochemical indices. Results The SW application amplified the growth, yield, minerals uptake, and quality of D. innoxia plants compared to the WW irrigated plants. The total chlorophyll, carotenoid, non-enzymatic antioxidants, viz. anthocyanin, flavonoids, phenolic compounds, and total alkaloids increased by 85, 38, 81, 50, 19, and 37%, respectively, above WW irrigated plants. The experiment terminated in enhanced leaf content of N, P, and K by 43, 118, and 48%, respectively. Moreover, stimulation of carbon and nitrogen metabolites in terms of proteins, soluble sugars, nitrate reductase (NR) activity, and nitric oxide (NO) content showed significant earliness in flowering time. The SW application improved not only Datura plants’ quality but also soil quality. After four weeks of irrigation, the WW irrigated plants encountered nutrient deficiency-induced stress evidenced by the high level of proline, H2O2, and MDA as well as high enzyme capabilities. Application of SW for irrigation of D. innoxia plant showed the improvement of secondary metabolites regulating enzyme phenylalanine ammonia-lyase (PAL), restored proline content, and cell redox status reflecting high optimal condition for efficient cellular metabolism and performance along the experiment duration. Conclusions These evidences approved the benefits of practicing SW to improve the yield and quality of D. innoxia and the feasibility of generalization on multipurpose plants grown in poor soil

Adapting date palm offshoots to long-term irrigation using groundwater in sandy soil

The date palm can grow in desert areas using high salinity groundwater by increasing the number of irrigation cycles. A field experiment was carried out on date palm cv. Sayer offshoots grown in sandy saline soil during the 2017 and 2018 growing seasons. The outcomes demonstrated that the application of saline (10 dS m–1) groundwater every four days increased plant height, number of new leaves, total chlorophyll, and relative water content. In turn, the hydrogen peroxide, malondialdehyde, and electrolyte leakage were reduced. Also, the effect of this treatment improved the growth of the plants, thus reduced the absorption of sodium, chloride, and increased potassium, then decreased the Na/K ratio. Cluster analysis showed two distinct cluster groups. In the first group, the dissimilarity between the treatments is illustrated by the influence of freshwater. While the second group showed the similarity between the treatments of four days and every week in the subgroup. Whereas treatment of two weeks duration shows the most detrimental effect on growth indices and chemical properties of offshoots. The utilization of saline groundwater in the water system of the date palm is the best option among the solutions possible in the current conditions of drought and thermal retention

Corn Cob-Derived Biochar Improves the Growth of Saline-Irrigated Quinoa in Different Orders of Egyptian Soils

Biochar is one of the important recycling methods in sustainable development, as it ensures the transformation of agricultural wastes into fertilizers and conditioners that improve soil properties and fertility. In the current study, corn cob-derived biochar (CB) was used to reduce the negative effects of saline water on quinoa (Chenopodium quinoa cv. Utosaya Q37) grown on Aridisols and Entisols, which are the major soil groups of Egyptian soils. Quinoa plants were cultivated in pot experiment and were irrigated with saline water (EC = 10 dS m−1). The experiment contained three treatments, including control without any treatment, biochar at a rate of 1% (w/w) (BC1), and biochar at a rate of 3% (w/w) (BC3). The findings of the current study showed that BC treatments realized significant effects on soil salinity, pH, soil organic matter (SOM), and plant availability and nutrients’ uptake in the two soils types. BC3 increased the SOM in Entisols and Aridisols by 23 and 44%; moreover, the dry biomass of quinoa plants was ameliorated by 81 and 41%, respectively, compared with the control. Addition of biochar to soil increased the nutrients’ use efficiencies by quinoa plants for the two studied Egyptian soils. Biochar addition caused significant increases in the use efficiency of nitrogen (NUF), phosphorus (PUE), and potassium (KUE) by quinoa plants. BC3 increased NUE, PUE, and KUS by 81, 81, and 80% for Entisols, while these increases were 40, 41, and 42% in the case of Aridisols. Based on the obtained results, the application of corn cob biochar improves the soil quality and alleviates the negative effects of saline irrigation on quinoa plants grown on Aridisols and Entisols Egyptian soils. Biochar can be used as a soil amendment in arid and semi-arid regions to reduce the salinity hazards

Hepatoprotective Effect of Curcumin on Hepatocellular Carcinoma Through Autophagic and Apoptic Pathways

Background and rationale: Microtubule-associated protein light chain 3-II (LC3-II), and Sequestosome-1 (SQSTM1) are proteins that can be used as markers for autophagic pathway. Bcl-2 protein is reported to be inversely correlated with apoptosis. We aimed to investigate the effects of curcumin on liver inflammation and fibrosis up to the first dysplastic stage of Hepatocellular carcinoma (HCC) induced by Thioacetamide (TAA) in rats and to clarify the effects of curcumin on LC3-II, SQSTM1, and Bcl-2. Male Sprague-Dawley rats were randomized into four groups: Control group, TAA group, Curcumin low-dose group, and Curcumin highdose group. The last three groups received TAA 200 mg/kg i.p. twice weekly for 18 weeks. Oxidative stress markers as hepatic malondialdehyde (MDA) concentration and superoxide dismutase (SOD) activity were measured by colorimetric methods. Hepatic SQSTM1 concentration was measured by ELISA, and gene expression levels of Bcl-2, and LC3-II were measured by RT-PCR.We also investigated the in vitro effect of curcumin on HepG2 cells viability through MTT assay, and the involvement of autophagy in this effect. Results: Curcumin increased the survival percent in rats, decreased -fetoprotein (AFP) concentration, and serum aspartate aminotransferase (AST) activity, and increased serum albumin concentration. Curcumin also significantly reduced oxidative stress in liver, inhibited apoptosis, and induced autophagy. In vitro, curcumin (50 μM) decreased HepG2 cells viabilityand the concentration of SQSTM1. Conclusions: Curcumin leads to protection against TAA induced HCC up to the first dysplastic stage through activating autophagic pathway and inhibiting apoptosis. Also, the antioxidant activity of curcumin almost prevents liver fibrosis

Induction of Catharanthus roseus Secondary Metabolites When Calotropis procera Was Used as Bio-Stimulant

Available information associated with Calotropis procera posted its phytotoxic effect as bio-herbicide scarce works studied its stimulatory/nutritive effect. A pot experiment was performed to assess the validity of using Calotropis procera (C. procera) leaves extract as a bio-stimulant for the growth and quality of a medicinal plant Catharanthus roseus (C. roseus) evaluated by some physio-biochemical indices. Different types of C. procera leaves extracts (CLEs) (methanolic, cold water and autoclaved water extracts) were delivered by two different modes of application. The results revealed that application of CLEs as irrigation or foliar spraying caused a stimulation effect on C. roseus plant. Root and shoot length, dry and fresh weight were significantly improved due to CLEs applications. C. roseus bioactive molecules such as anthocyanins, phenolics, flavonoids, alkaloids, ascorbic acid, reduced glutathione and α-tocopherol were abundance increased significantly with CLEs applications. Reactive oxygen species (ROS) decreased explaining the involvement of CLEs in induction of antioxidant enzymes catalase, ascorbate peroxidase, polyphenol oxidase, guaiacol peroxidase and glutathione-S-transferase for modifying cell oxidative status witnessed by lower lipid peroxidation that kept below the untreated plants’ baseline reflected the improvement of growth and quality rather than phytotoxic effect. The promotion of wholesome-promoting secondary metabolites by CLEs was closely correlated to elevated phenylalanineammonialyase activity. The comparable efficient effect induced by all treatments might be judged by the relation between C. procera phytochemicals and C. roseus metabolism (donor-receiver relation). It is concluded that application of CLEs can be a promising approach for improving the yield and quality of plants despite using polluting fertilizers. The current investigation may provide a matrix for coming studies to seek illustration of numerous plants’ response to C. procera extracts

Compost Enhances Forage Yield and Quality of River Saltbush in Arid Conditions

High temperatures and water scarcity are among the main obstacles to producing fodder in arid regions. Saltbush shrubs are used for livestock in many arid regions, especially in saline conditions, due to their high salt tolerance. The produced forage materials under these saline conditions are often low in quantity and quality. This article presents field studies that were conducted for two growing seasons to evaluate the forage yield and quality of river saltbush (Atriplex amnicola Paul G. Wilson) as a function of compost application. The plants were cultivated in saline soil (15 dS m−1), and compost was added at four rates (0, 5, 10, and 15 t ha−1). River saltbush plant produced 9.23−15.60 t ha−1 of stems and 4.25−7.20 t ha−1 of leaves yearly (over all the treatments). The crude protein (CP) ranged between 48−70 g kg−1 in the stems and between 160−240 g kg−1 in the leaves (over all the treatments). The forage yield, crude protein, dry matter, and mineral contents of the tested plant increased significantly (p −1 of compost reduced the Na+ concentrations in the leaves by 14, 16, and 19% (as means of two years) compared with the control. In the same trend, these rates reduced the oxalate concentrations in the leaves by 38, 30, and 29% (as means of two years) compared with the control. Our results show that compost application improves the activity of polyphenol oxidase (PPO) and catalase (CAT). Compost reduces the adverse impacts of soil salinity by improving the photosynthesis process and increasing the activity of antioxidant defense. Compost also enhances the growth of river saltbush plants cultivated in saline soils, thus, enhancing their value as animal feed. Halophyte plants can be used to utilize saline soils that are not suitable for traditional production. Compost addition is a good agricultural strategy to increase growth and reduce the negative effects of salts

Shrimp-Waste-Derived Biochar Induces Metal Toxicity Tolerance of Wastewater-Irrigated Quinoa (Chenopodium quinoa)

The scarcity of high-quality water resources may lead to the use of lower quality water for plant production. Quinoa (Chenopodium quinoa) plants have great potential for human nutrition, but poor water quality, such as metal contamination in wastewater, affects the seed quality. This study aims to investigate the effects of shrimp-waste-derived biochar (SWB) on the uptake of toxic metals from wastewater by quinoa plants. Additionally, the study investigates how quinoa plants’ antioxidant defenses respond to wastewater and SWB treatments. Shrimp-waste-derived biochar (SWB) was prepared by pyrolysis at 350 °C for 3 h and added to the soil at the levels of 0, 1, and 2% (based on soil weight), which are namely C, SWB1, and SWB2, respectively. SWB was applied to quinoa plants cultivated in pots filled with sandy soil and irrigated with fresh or wastewater for a continuous 90 days. The wastewater was contaminated with manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb). Quinoa seeds that were irrigated with wastewater had Cd and Pb concentrations that were above the allowable levels (for human consumption) in the absence of biochar (C) or addition of SWB1. Wastewater significantly reduced quinoa growth and photosynthetic pigments, while SWB significantly mitigated the metal toxicity and improved growth. SWB2 significantly reduced the Pb and Cd concentrations in quinoa leaves by 29 and 30% compared with C. The Cd and Pb concentrations in quinoa seeds were safe for human consumption and below the maximum allowable limits when the soil was amended with SWB2. SWB improved the synthesis of photosynthetic pigments and increased the activity of antioxidant enzymes such as polyphenol oxidase and ascorbate peroxidase. SWB reduced the toxic metal availability and uptake, mitigated the oxidative stress, and minimized the levels of malondialdehyde and hydrogen peroxide. The SWB addition stimulated quinoa’s antioxidant defense and protected plant cells by eliminating reactive oxygen species. The addition of 2% (w/w) shrimp waste biochar improved the quality of quinoa seeds irrigated with wastewater and decreased their toxic metal content. The obtained results contribute to sustainable development and the exploitation of wastewater to irrigate quinoa plants in arid degraded soil; additionally, it also helps in the recycling of shrimp waste