Lead (Pb) toxicity is a significant environmental issue, especially in areas with a past of industrial activities and mining. The existence of Pb in the soil can have negative impacts on plant growth and development, and it can also pose a risk to human health through the food chain. Acidified carbon has shown promise as an effective management technology for mitigating Pb toxicity. This study provides important insights into the potential of acidified biochar as a low-cost and eco-friendly method for managing Pb-contaminated soils. The current study explores the effectiveness of acidified biochar (AB) in alleviating Pb stress in mint. The study involved two levels of Pb (0 = control and 200 mg/kg Pb) and four levels of AB as treatments (0, 0.45, 0.90, and 1.20%). Results indicate that 1.20% AB was the most effective treatment, significantly decreasing root and shoot Pb concentration while enhancing shoot and root fresh and dry weight, shoot and root length, and shoot and root N, P, and K concentration. Moreover, a significant decrease in MDA (0.45AB, 0.90AB, and 1.20AB caused a decline in MDA content by 14.3%, 27.8%, and 40.2%, respectively) and an increase in ascorbic acid (0.45AB, 0.90AB, and 1.20AB led to an increase in ascorbic acid content of 1.9%, 24.8%, and 28.4%, respectively) validated the effectiveness of 1.20% AB compared to the control. Adding 0.45AB, 0.90AB, and 1.20AB led to an increase in soluble sugar content of 15.6%, 27.5%, and 32.1%, respectively, compared to the treatment without AB. Further investigations at the field level are suggested to confirm the efficacy of 1.20% AB as the best treatment against Pb toxicity in saline soil conditions.

Cadmium stress significantly affects plant growth by disrupting essential physiological and biochemical functions. It slows nutrient intake, causing slowed development and decreased biomass. Cd also produces reactive oxygen species, causing oxidative stress, which harms cell components like lipids, proteins, and DNA. This lowers chlorophyll levels, making photosynthesis difficult and stunting development. Cd’s toxicity affects hormone balance, enzyme activity, and cell structural integrity, leading to poor plant growth and decreased agricultural output. Acidified biochar (BC) can effectively overcome this problem. Biochar features high cation exchange capacity (CEC) and oxygen-containing functional groups may aid in the immobilization of heavy metals in soil via surface complexation and precipitation. Cd immobilization can be increased by treating biochar with acid, which exposes additional adsorption sites. It can significantly enhance plant growth by improving soil structure, encouraging water retention, and improving microbial activity as a slow-release nutrient. This study investigates the effects of combining BC as amendments to spinach, both with Cd and without stress. Four treatments (control, 0.45BC, 0.90BC, and 1.20BC) were applied using a completely randomized design in four replications. Results showed that 1.20BC treatment showed a significant increase in shoot fresh weight (86.21%), root fresh weight (96.20%), shoot dry weight (223.24%), root dry weight (42.38%), total soluble sugar (16.05%), total soluble protein (54.70%), compared to the 0BC under 20 mg Cd/kg soil contamination. Additionally, there were notable improvements in chlorophyll a (121.26%), chlorophyll b (10.91%), and total chlorophyll (32.12%) above the control in Cd stress, also showing the potential of 1.20BC. A significant increase in N, P, and K concentrations of shoot and root of spinach was also noted, which validated the effectiveness of 1.20BC over 0BC under cadmium stress. It is concluded that applying 1.20BC can potentially alleviate the Cd-induced stress in spinach.

Salinity stress is one of the major hurdles in agriculture which adversely affects crop production. It can cause osmotic imbalance, ion toxicity that disrupts essential nutrient balance, impaired nutrient uptake, stunted growth, increased oxidative stress, altered metabolism, and diminished crop yield and quality. However, foliar application of osmoprotectant is becoming popular to resolve this issue in crops. These osmoprotectants regulate the cellular osmotic balance and protect plants from the detrimental effects of high salt concentrations. Furthermore, the role of arbuscular mycorrhizae (AMF) is also established in this regard. These AMF effectively reduce the salinity negative effects by improving the essential nutrient balance via the promotion of root growth. That’s why keeping in mind the effectiveness of osmoprotectants current study was conducted on cotton. Total of six levels of γ-Aminobutyric acid (GABA = 0 mM, 0. 5 mM, and 1 mM) and ectoine (ECT = 0 mM, 0.25 mM, and 0.5 mM) were applied as treatments in 3 replications. Results showed that 0.5 mM γ-Aminobutyric acid and ectoine performed significantly best for the improvement in cotton growth attributes. It also caused significant enhancement in K and Ca contents of the leaf, stem, bur, and seeds compared to the control. Furthermore, 0.5 mM γ-Aminobutyric acid and ectoine also caused a significant decline in Cl and Na contents of leaf, stem, bur, and seeds of cotton compared to control under salinity stress. A significant enhancement in chlorophyll contents, gas exchange attributes, and decline in electrolyte leakage validated the effectiveness of 0.5 mM γ-Aminobutyric acid and ectoine over control. In conclusion, 0.5 mM γ-Aminobutyric acid and ectoine have the potential to mitigate the salinity stress in cotton.

Lead (Pb) is a stress that can cause problems with several aspects of a plant’s metabolism, potentially impeding the plant’s ability to grow and develop. The use of gibberellic acid (GA3), quantum dot biochar (QDBC), and rhizobacteria (RB) can be effective methods to overcome this problem. Gibberellic acid is a crucial plant hormone that regulates plant growth, cell division, tissue differentiation, flowering, photosynthesis, and transpiration rate. It also significantly impacts crop resilience to stress, affecting plant morphology, enzymatic activity, and physiology. Biochar, a soil supplement, enhances plant development soil health, and reduces stress effects. Due to its large surface area and porosity, it increases soil water-holding capacity, nutrient retention, and microbial activity. Quantum dots, semiconductor nanoparticles, have been proposed as a potential method to alleviate plant stress by acting as antioxidants, reducing oxidative stress, and controlling nutrient and growth regulators. Rhizobacteria, soil bacteria in plant roots, stimulate plant growth, nutrient absorption, and harvesting capacity. They produce phytohormones, increase mineral and nitrogen accessibility, and can induce systemic resistance (ISR), affecting plant defense. This study investigates the effects of combining GA3, QDBC, and RB as amendments to fenugreek, both with 500 Pb stress and without Pb stress. Treatments (control, 0.25 GA3mg/L-QDBC, 0.5 GA3mg/L-QDBC, 0.25 GA3mg/L-QDBC + RB, and 0.5 GA3mg/L-QDBC + RB) were applied in six replications using a completely randomized design. Results demonstrate that the combination of 0.5 GA3mg/L-QDBC + RB with 500 Pb stress led to significant enhancements in fenugreek shoot fresh weight (15.62%), root fresh weight (73.53%), shoot dry weight (24.00%), and root dry weight (36.53%) compared to the control. Additionally, there were notable improvements in chlorophyll a (57.23%), chlorophyll b (19.21%), and total chlorophyll (36.23%) compared to the control under Pb stress, also showing the potential of 0.5 GA3mg/L-QDBC + RB with 500 Pb stress. The study suggests that combining 0.5 GA3mg/L-QDBC + RB with 500 Pb stress can effectively mitigate Pb stress in fenugreek.

Soil heavy metal pollution poses a significant environmental risk to human health and plant growth. Gibberellic acid (GA) and γ-aminobutyric acid (GABA) are effective methods for resolving this issue. GA regulates growth mechanisms such as seed germination, flowering, and stem elongation. Plants use GABA, a signaling molecule, to control physiological processes, growth, and responses to stress. This substance plays a crucial role in the interactions between hormones and plant defense, as evidenced by its effects on photosynthesis, food absorption, and stomatal behavior. The study aimed to determine how GABA and GA amendments affected tomato plants under no toxicity and Pb toxicity. The study included four treatments (0, GA, GABA, and GA + GABA) in four replications following a completely randomized design. Notably, the GA + GABA treatment led to considerable enhancements in fresh weight (88.98%), dry weight (68.28%), shoot length (39.98%), and root length (115.43%) compared to the control under Pb toxicity. Moreover, GA + GABA treatment significantly increased tomato chlorophyll a (161.72%), chlorophyll b (93.33%), and total chlorophyll content (112.45%) under Pb stress toxicity, confirming the effectiveness of GA + GABA treatment. In conclusion, GA + GABA is recommended as the best amendment to mitigate Pb stress in tomato plants. Our findings have broader implications for GA + GABA application, offering a potential technology to enhance sustainable crop production by improving plant growth and yield in Pb-contaminated soils. More investigations are suggested at field levels under different agroclimates on different crops for the declaration of GA + GABA as the best amendment for alleviating different heavy metal pollutions and sustainable agriculture productions.

Lead (Pb) contamination in soil affects plant nitrogen assimilation and reduces seed germination and plant water relations. Pb exposure also reduces carotenoid, chlorophyll, carbon dioxide, assimilation, and photosynthetic rates in plants. The use of Ethylenediaminetetraacetic acid (EDTA), and Gibberellic acid GA3 is an effective amendment to mitigate this problem. EDTA improves plant growth by increasing the bioavailability of essential ions in the soil, allowing plants to better absorb nutrients. Its efficient, environmentally friendly, and biodegradable nature makes it ideal for enhancing metal uptake and promoting healthy plant development in metal-polluted soils. GA3 improves plant growth by different mechanisms such as stem elongation, flowering and seed germination. The combined application of the GA3 and EDTA as an amendment on spinach still needs scientific justification. This study investigates the combined impact of GA3 and EDTA as an amendment on spinach growth. The 10ppmGA3, 0.5%EDTA, 10ppmGA3 + 0.5%EDTA, 1%EDTA, and 10ppmGA3 + 1%EDTA treatments were administered in four replicates using a completely randomized design (CRD), both with and without Pb stress. Results demonstrate that 10ppmGA3 + 1%EDTA exhibits a rise in spinach shoot fresh weight (97.73%), root fresh weight (89.98%), shoot dry weight (96.72%), and root dry weight (100.00%) over the control in 500Pb stress. The study found that 10ppmGA3 + 1%EDTA significantly increased spinach chlorophyll a (64.11%), chlorophyll b (98.34%), and total chlorophyll (74.37%) in 500ppmPb stress than the control. In conclusion, 10ppmGA3 + 1%EDTA is the suggested amendment for mitigating Pb stress in spinach.