Phytoremediation potential of Pistia stratiotes, Eichhornia crassipes, and Typha latifolia for chromium with stimulation of secondary metabolites.

Anthropogenic activities have significantly polluted the natural environments all over the world. Leather processing industries release toxic heavy metals through their effluents posing a great threat to the environment. Chromium (Cr) is the major component of tannery effluents. We designed this experiment with the aim to remediate Cr from effluents of tanneries through phytoremediation. We selected three native macrophytes i.e. Pistia stratiotes, Eichhornia crassipes, and Typha latifolia to grow in a set of Constructed Wetland systems (CWs) with a continuous supply of tannery wastewater. T. latifolia was the most efficient phytoremediator of these macrophytes as it reduced the Cr content by 96.7%. The effluent after passing through the CWs containing T. latifolia showed only 0.426 mg/L Cr content. All macrophytes showed an enhanced phytochemical activity such as total antioxidant activity (TAA), total reduction potential (TRP), total phenolic content (TPC), total flavonoid content (TFC), and DPPH radical scavenging activity (DPPH) substantially. The activation of antioxidant mechanism may have contributed towards robust defense system of these plants for survival in excessive Cr contaminated media. Also, these macrophytes showed a positive relationship in reducing Cr content from tannery wastewater. Results of this study could help in effective sustainable management of aquatic environments contaminated with metal pollutants from human activities.

Unveiling the detrimental effects of polylactic acid microplastics on rice seedlings and soil health.

The environmental impact of biodegradable polylactic acid microplastics (PLA-MPs) has become a global concern, with documented effects on soil health, nutrient cycling, water retention, and crop growth. This study aimed to assess the repercussions of varying concentrations of PLA-MPs on rice, encompassing aspects such as growth, physiology, and biochemistry. Additionally, the investigation delved into the influence of PLA-MPs on soil bacterial composition and soil enzyme activities. The results illustrated that the highest levels of PLA-MPs (2.5%) impaired the photosynthesis activity of rice plants and hampered plant growth. Plants exposed to the highest concentration of PLA-MPs (2.5%) displayed a significant reduction of 51.3% and 47.7% in their root and shoot dry weights, as well as a reduction of 53% and 49% in chlorophyll a and b contents, respectively. The activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX) in rice leaves increased by 3.1, 2.8, 3.5, and 5.2 folds, respectively, with the highest level of PLA-MPs (2.5%). Soil enzyme activities, such as CAT, urease, and dehydrogenase (DHA) increased by 19.2%, 10.4%, and 22.5%, respectively, in response to the highest level of PLA-MPs (2.5%) application. In addition, PLA-MPs (2.5%) resulted in a remarkable increase in the relative abundance of soil Proteobacteria, Nitrospirae, and Firmicutes by 60%, 31%, and 98.2%, respectively. These findings highlight the potential adverse effects of PLA-MPs on crops and soils. This study provides valuable insights into soil-rice interactions, environmental risks, and biodegradable plastic regulation, underscoring the need for further research.

Interplay between edaphic and climatic factors unravels plant and microbial diversity along an altitudinal gradient.

Altitude influences biodiversity and physiochemical soil attributes in terrestrial ecosystems. It is of immense importance to know the patterns of how interactions among climatic and edaphic factors influence plant and microbial diversity in various ecosystems, particularly along the gradients. We hypothesize that altitudinal variation determines the distribution of plant and microbial species as well as their interactions. To test the hypothesis, different sites with variable altitudes were selected. Analyses of edaphic factors revealed significant (p < 0.001) effects of the altitude. Soil ammonium and nitrate were strongly affected by it contrary to potassium (K), soil organic matter and carbon. The response patterns of individual taxonomic groups differed across the altitudinal gradient. Plant species and soil fungal diversity increased with increasing altitude, while soil archaeal and bacterial diversity decreased with increasing altitude. Plant species richness showed significant positive and negative interactions with edaphic and climatic factors. Fungal species richness was also significantly influenced by the soil ammonium, nitrate, available phosphorus, available potassium, electrical conductivity, and the pH of the soil, but showed non-significant interactions with other edaphic factors. Similarly, soil variables had limited impact on soil bacterial and archaeal species richness along the altitude gradient. Proteobacteria, Ascomycota, and Thaumarchaeota dominate soil bacterial, fungal, and archaeal communities, with relative abundance of 27.4%, 70.56%, and 81.55%, respectively. Additionally, Cynodon dactylon is most abundant plant species, comprising 22.33% of the recorded plant taxa in various study sites. RDA revealed that these communities influenced by certain edaphic and climatic factors, e.g., Actinobacteria strongly respond to MAT, EC, and C/N ratio, Ascomycota and Basidiomycota show strong associations with EC and MAP, respectively. Thaumarcheota are linked to pH, and OM, while Cyperus rotundus are sensitive to AI and EC. In conclusion, the observed variations in microbial as well as plant species richness and changes in soil properties at different elevations provide valuable insights into the factors determining ecosystem stability and multifunctionality in different regions.

Green Synthesis of Withania coagulans Extract-Mediated Zinc Oxide Nanoparticles as Photocatalysts and Biological Agents.

Recently, biosynthesized nanoparticles (NPs) have played a vital role as an alternative to physical and chemical methods. Here, a distinctive bioinspired synthesis of zinc oxide nanoparticles (ZnO NPs) has been introduced using leaf extracts of Withania coagulans as the reducing agent by using distilled water and methanol. The synthesized catalysts were analyzed through ultraviolet-visible spectroscopy, dynamic light scattering, scanning electron microscopy, Fourier transform infrared, energy-dispersive X-ray analysis, and X-ray diffraction for NP synthesis, morphology, functional group, elemental composition, and peak crystallinity analysis. The phytochemical analysis of 2,2-diphenyl-1-picrylhydrazyl (DPPH), total flavonoid content, total alkaloid content, and total phenolic content of the crude methanolic extract of the plant was also performed, suggesting the greatest potential as the supporting material for ZnO NPs. The NPs were investigated for their catalytic efficiency in the degradation of dyes (rhodamine B dye) and against important human food-borne pathogens (Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli). ZnO NPs exhibited a strong catalytic activity in the degradation of dyes and against bacteria. The results also showed an enhanced activity of ZnO NPs of methanolic extract (ZnO-M) composites compared to zinc oxide of distilled water (ZnO-D). The % age degradation of the dye, Kapp, and linear relationship were obtained from pseudo-first-order kinetics. The highest reduction rate in 30 and 60 min was observed under sunlight by ZnO-M and ZnO-D, respectively. The rate constant Kapp for the reduction of the dye was 13.6 × 10-1 min-1 and 6.8 × 10-1 min-1, respectively (numerical values). For ZnO-M, ln(Kapp) ≈ 0.309. For ZnO-D, ln(Kapp) ≈ -0.385. These rate constants represent the degradation of the dye in the presence of ZnO-M and ZnO-D catalysts. In addition, NPs were found to be most active against S. aureus (18 mm in the case of ZnO-M and 15 mm in the case of ZnO-D) than P. aeruginosa and E. coli. The results suggested that the prepared ZnO NPs could be used in pharmaceutical industries as well as photocatalysts. ZnO-M had greater control over particle size and morphology, potentially resulting in smaller, more uniform NPs. ZnO-D achieved fine size control but not potentially better than that compared to organic solvents.

Relative biochemical and physiological docking of cucumber varieties for supporting innate immunity against Podosphaera xanthii.

Powdery mildew in cucumber is caused by the Podosphaera xanthii. No strategy for improving disease resistance can be successful in the absence of thorough insights into the physiological and biochemical responses of cucumber plants to powdery mildew. Therefore, a field experiment was executed to evaluate five commercial cucumber varieties (V1: Dynasty, V2: Long green, V3:Desi Kheera, V4:Thamin II, V5:Cucumber 363) for their inherent immunity to powdery mildew. Upon inoculating cucumber plants with Podosphaera xanthii, we noted differential responses among the varieties. Compared to other varieties, V1 and V2 showed higher values (P ≤ 0.05) for chlorophyll-a under control and pathogen-attacked plants respectively. The minimum value of anthocyanin content (-53.73%) was recorded in V3 as compared to other varieties post pathogen infection. All pathogen-infected cucumber varieties showed a considerable (P ≤ 0.05) loss in flavonoid content except V2. The maximum destruction for Phenolics under powdery mildew (179%) were recorded in V4, whereas V1 exhibited maximum phenolic content under control conditions. In pathogen-infected plants, the minimum AsA was recorded in V5 as compared to all other varieties. Pathogen invasion impacted significantly (P ≤ 0.05) the activity of superoxide dismutase (SOD). Besides, cucumber plants after pathogen inoculation resulted in a considerable (P ≤ 0.05) increase of peroxidase (POD) activity in V1 (5.02%), V2 (7.5%), and V3 (11%) in contrast to V4. Our results confirmed that cucumber varieties perform differently, which was brought on by distinct metabolic and physiological modifications that have an impact on growth and development. The changes in different attributes were correlated with cucumber resistance against powdery mildew. The results would help us fully harness the potential of these varieties to trigger disease management initiatives and defense responses.

Genetic modification strategies for enhancing plant resilience to abiotic stresses in the context of climate change.

Enhancing the resilience of plants to abiotic stresses, such as drought, salinity, heat, and cold, is crucial for ensuring global food security challenge in the context of climate change. The adverse effects of climate change, characterized by rising temperatures, shifting rainfall patterns, and increased frequency of extreme weather events, pose significant threats to agricultural systems worldwide. Genetic modification strategies offer promising approaches to develop crops with improved abiotic stress tolerance. This review article provides a comprehensive overview of various genetic modification techniques employed to enhance plant resilience. These strategies include the introduction of stress-responsive genes, transcription factors, and regulatory elements to enhance stress signaling pathways. Additionally, the manipulation of hormone signaling pathways, osmoprotectant accumulation, and antioxidant defense mechanisms is discussed. The use of genome editing tools, such as CRISPR-Cas9, for precise modification of target genes related to stress tolerance is also explored. Furthermore, the challenges and future prospects of genetic modification for abiotic stress tolerance are highlighted. Understanding and harnessing the potential of genetic modification strategies can contribute to the development of resilient crop varieties capable of withstanding adverse environmental conditions caused by climate change, thereby ensuring sustainable agricultural productivity and food security.

Detoxifying the heavy metals: a multipronged study of tolerance strategies against heavy metals toxicity in plants.

Heavy metal concentrations exceeding permissible limits threaten human life, plant life, and all other life forms. Different natural and anthropogenic activities emit toxic heavy metals in the soil, air, and water. Plants consume toxic heavy metals from their roots and foliar part inside the plant. Heavy metals may interfere with various aspects of the plants, such as biochemistry, bio-molecules, and physiological processes, which usually translate into morphological and anatomical changes. They use various strategies to deal with the toxic effects of heavy metal contamination. Some of these strategies include restricting heavy metals to the cell wall, vascular sequestration, and synthesis of various biochemical compounds, such as phyto-chelators and organic acids, to bind the free moving heavy metal ions so that the toxic effects are minimized. This review focuses on several aspects of genetics, molecular, and cell signaling levels, which integrate to produce a coordinated response to heavy metal toxicity and interpret the exact strategies behind the tolerance of heavy metals stress. It is suggested that various aspects of some model plant species must be thoroughly studied to comprehend the approaches of heavy metal tolerance to put that knowledge into practical use.

Integrative Evaluation of the Ecological Hazards by Microplastics and Heavy Metals in Wetland Ecosystem.

This study was performed to evaluate the impact of microplastics and heavy metals (Pb, Cd, Cr, Cu, Zn, Ni) on sediments, water, aquatic plants (Pistia stratiotes, Alternanthera philoxeroides, and Ipomoea carnea), and fish (Labeo rohita) samples collected from five different sites in the Bajwat wetlands in Sialkot, Pakistan. The concentrations of Pb, Cd, and Cr were above the permissible limits devised by WHO in all the ecosystem components (i.e. sediments, water, plants, and fish) at all sites. The maximum amount of microplastic particles (2317 microplastic particles per kg of sediments) was recorded at Site 1. The filaments were the most commonly found type of microplastics. Plants and fish samples also showed considerable concentration of metals. The multivariate statistical analysis revealed anthropogenic sources of elevated concentrations of metal elements which could cause adverse biological effects in the ecosystem.

Glutathione treatment suppresses the adverse effects of microplastics in rice.

Oryza sativa is grown worldwide and exhibit sensitivity to different stresses. Exponential increase in microplastics in agroecosystems is damaging and demand pragmatic strategies to protect growth and yield losses. We evaluated exogenous application of different doses of glutathione (GSH) for mediation of physiological traits of rice plants experiencing two different MPs i.e. PET and HDPE in root zone. All the rice seedlings exhibited MP-induced significant (P ≤ 0.001) growth inhibition compared to the control plants. GSH application (T3) significantly increased the shoot fresh weight (8.80%), root fresh weight (19.22%), shoot dry weight (13.705%), root dry weight (25.52%), plant height (5.75%) and 100-grain weight (9.36%), compared to control plants. GSH treated plants (T4) showed a recovery mechanism by managing the marginal rate of reduction of all photosynthetic and gas exchange attributes by showing 34.44, 20.98, 34.83, 42.16, 39.70, and 51.38% reduction for Chl-a, Chl-b, total cholophyll, photosynthetic rate (A), transpiration rate (E), and stomatal conductance (Gs), respectively, compared to control plants. Under 5 mg L-1 HDPE and PET, rice seedlings without GSH treatment responded in terms of increase in total soluble sugar, total free amino acid, glutathione, glutathione disulfide contents, while total soluble protein and ascorbic acid contents decreased significantly, compared with control plants. Corrleation matrix revealed positive relationship between GSH and improvement in studied attributes. Moreover, exogenous GSH improved rice growth and productivity to counter the negative role of MPs. This unique study examined the effects of GSH on rice plants growing in MP-contaminated media and revealed how exogenous GSH helps plants survive MP-stress.

Interactive effects of polystyrene microplastics and Pb on growth and phytochemicals in mung bean (Vigna radiata L.).

Interaction of different pollutants can aggravate hazards to biotic components in agroecosystems. Microplastics (MPs) are especially needed to be focused on because of their increasing use in life around the globe. We investigated the interactive impacts of polystyrene microplastics (PS-MP) and lead (Pb) on mung bean (Vigna radiata L.). Toxicity of MPs and Pb directly impeded V. radiata attributes. In combination i.e., M2P2 (40 µM Pb + 4.0 mg L-1 MPs) predominantly reduced the shoot root fresh and dry weights. \ Pb and PS-MP impaired the Rubisco activity and chlorophyll contents. The dose dependent relationship (M2P2) discomposed indole 3-acetic acid by 59.02%. Individual treatments P2 (40 µM Pb) and M2 (4.0 mg L-1 MPs) respectively instigated a decline (44.07% and 27.12%) in IBA, while ABA was elevated. M2 significantly enhanced the contents of Alanine (Ala), Arginine (Arg), Proline (Pro), and glycine (Gly) by 64.11%, 63%, and 54% compared to control. Lysine (Lys) and Valine (Val) presented a converse relationship with other amino acids. Except for control, a gradual decline in yield parameters were observed in individual and combined applications of PS-MP. Proximate composition of carbohydrates, lipids and proteins also reflected a clear decrease in these compounds after combined application of Pb and MPs. Although, individual doses caused a decline in these compounds but effect of combined doses Pb and PS-MP was highly significant. Our results demonstrated the toxicity effect of Pb and MP in V. radiata attributes that is mainly linked with cumulative physiological and metabolic perturbations. These collective negative impacts of different doses of MPs and Pb on V. radiata would certainly pose serious implications for humans.

Synergistic impact of two autochthonous saprobic fungi (A. niger and T. pseudokoningii) on the growth, ionic contents, and metals uptake in Brassica juncea L. and Vigna radiata L. under tannery solid waste contaminated soil.

Unrestricted disposal of tannery solid waste (TSW) into agricultural soils has resulted in the contamination of heavy metals (HMs) such as chromium (Cr) cadmium (Cd), Copper (Cu), and Zinc (Zn) along with the severe potential to degrade the environmental quality around the world. In the present study, a combined phyto- and myco-remediation strategy was evaluated to enhance the growth, ionic contents, and phytoextraction potential of Brassica juncea and Vigna radiata for HMs from TSW-contaminated soil. A pot experiment was conducted in the greenhouse using single or combined inoculation of Trichoderma pseudokoningii (Tp) and Aspergillus niger (An) in B. juncea and V. radiata under TSW-contaminated soil at different doses (0, 50, and 100%). The results showed that the growth parameters of both B. juncea and V. radiata were severely affected under 50 and 100% TSW treatment. The combined inoculation of both the fungal species ameliorated the positive impacts of 50 and 100% TSW application on growth and ionic contents accumulation in B. juncea and V. radiata. The combined application of An + Tp at 100% TSW enhanced the shoot length (87.8, 157.2%), root length (123.9, 120.6%), number of leaves (184.2, 175.0%), number of roots (104.7, 438.9%), and dry weight (179.4, 144.8%) of B. juncea and V. radiata, respectively as compared to control with any fungal treatment at 100% TSW. A single application of An at different doses of TSW enhanced the metal concentration in B. juncea, whereas Tp increased the concentration of the metals in V. radiata. The concentration of Cr in roots (196.2, 263.8%), shoots (342.4, 182.2%), Cu in roots (187.6, 137.0%), shoots (26.6, 76.0%), Cd in roots (245.2, 184.6%), shoots (142.1, 73.4%), Zn in roots (73.4, 57.5%), shoots (62.9, 57.6%), in B. juncea were increased by the application of An at 50 and 100% treatment levels of TSW, respectively compared to control (C). Moreover, the HMs (Cr, Cu, Cd, and Zn) uptake was also improved under 50 and 100% TSW with the combined inoculation of Tp + An in both B. juncea and V. radiata. In conclusion, the combined inoculation of Tp + An was more effective in metal removal from TSW-treated soil.NOVELTY STATEMENTLimited studies have been conducted on filamentous fungi systematically under metal-contaminated sites for their diversity, metal tolerance, and their potential in enhancing the phytoremediation potential of different crop plants.In the present study, single and/or combined inoculation of fungal strains was found effective in alleviating different metals stress in tannery solid waste contaminated soil by improving defense mechanisms and plant growth due to the association between fungal strains and plants.The combined application of both fungal strains had an additive effect in enhancing the bioaccumulation capacity of B. juncea and V. radiata compared to their single inoculation.

Ecological health risk assessment of microplastics and heavy metals in sediments, water, hydrophytes (Alternanthera philoxeroides, Typha latifolia, and Ipomoea carnea), and fish (Labeo rohita) in Marala wetlands in Sialkot, Pakistan.

For the ecological risk assessment of heavy metals and microplastics in Marala wetlands in Sialkot, Pakistan, samples of sediments, water, aquatic plants (Alternanthera philoxeroides, Typha latifolia, and Ipomoea carnea), and fish (Labeo rohita) were studied from five different locations. Pb, Cd, and Cr concentrations were above permissible limits devised by WHO in sediments and water at most of sites. High concentrations of Cd were recorded in water samples compared to sediments with maximum values recorded at Site-2 (52.08 ± 9.55 mg kg-1) and Site-5 (62.29 ± 10.12 mg kg-1). The maximum concentrations of Cr (7.23 ± 0.40 mg kg-1) and Pb (22.87 ± 0.83 mg kg-1) were found at Site-4 in water samples. The maximum abundance of microplastics (3047 pieces kg-1 of sediments) was at Site-1 with filaments in the highest proportion among the other types. Zn, Ni, and Cu remained generally low in concentrations in both sediments and waters. Plants showed accumulation of heavy metals, notably the amount of Cd (33.36 ± 0.26 mgkg-1) and Ni (163.3 ± 1.30 mgkg-1) absorbed by T. latifolia and A. philoxeroides, respectively were high. Also, photosynthetic pigments in plants seemed to be affected. However, estimated daily intake (EDI) and provisional tolerable weekly intake (PTWI) calculations for the human population consuming fish from this wetland remained below the FAO/WHO limits. PCA analysis revealed the anthropogenic origin of metals that might be causing adverse effects on the biota which depend on this wetland for their food.

Nerium oleander could be used for sustainable management of traffic-borne elemental-enriched roadside soils.

Metal pollutants released from motor vehicles are deposited in roadside environments. Metals are non-biodegradable and biomagnify in the food chain causing significant health hazards at all levels of the ecosystem. Hence, management of contaminated roadside verges is critically important and should be kept in mind while planning specific management strategies of such areas. Native vegetation could help to decontaminate heavy metal polluted soils in the best sustainable way. Therefore, this study was designed to assess the potential of Nerium oleander to accumulate heavy metals commonly released by automobiles such as Pb, Cd, Ni, and Zn along with various C and N compounds from five different locations along a busy road in Punjab, Pakistan, during summer and winter seasons. N. oleander showed the ability to absorb C, N, and heavy metals Pb and Cd; the maximum concentration of Pb and Cd was 8.991 mg kg-1 and 0.599 mg kg-1, respectively. These pollutants negatively affected photosynthetic pigments, gas exchange attributes, soluble proteins, and free amino acids. But antioxidant activity of N. oleander was found to be increased in both seasons. The metal accumulation in the plant was higher in the summer though. We highly recommend that by growing N. oleander at roadside verges for decontamination of vehicular pollutants could lead to sustainable management of these corridors.

Foliar application of silver nanoparticles mitigated nutritional and biochemical perturbations in chilli pepper fertigated with domestic wastewater.

Due to environmental pollution, crop growth and productivity are threatened at different levels. Recapitulation of changes in plant bodies due to water pollution and mitigating strategies reveal the need for précised actions to save crop losses. The present study was carried out to estimate modulations in growth, mineral homeostasis, and nutrient profile of fruits in Capsicum annum L. grown with three concentrations of wastewater (25, 50, 100%) and two levels of silver nanoparticles (40 and 80 mg/L AgNPs). It has been reported that ion accumulation patterns from wastewater clearly vary among crops. Our findings manifested that the application of AgNPs significantly improved the mineral ions in different plant tissues, that ultimately helped to improve growth. Highest improvements were recorded for root shoot P (316 and 197%) at T9 (80 mg/L AgNPs + normal water), while K (273 and 262%), Mg (638 and 916%), and Ca (148 and 273%), at T11 (80 mg/L AgNPs + 50% Wastewater), in comparison with control. Such reduction in elemental uptake that remain detrimental even at low concentrations positively correlates with growth and nutrition of Capsicum plants. Another facet of our observation is dose-dependent improvement in nutritive attributes of fruits i.e., crude fibers, proteins, and carbohydrates by AgNPs. T8 (40 mg/L AgNPs + 100% Wastewater), improved nutritional attributes such as P (55%), Mn (44%), Zn (38%), Carbohydrates (62%), Crude fat (38%), and Fibers (49%) as compared to control. Application of silver nanoparticles (AgNPs) combined with untreated wastewater (WW) reduced the hazards of contaminants in plants. The finding of the current study suggested that AgNPs are a cost-efficient and environment friendly material having the potential to mitigate harmful impacts of WW on plants.

Impact of plastic mulching as a major source of microplastics in agroecosystems.

The contamination of agroecosystems by microplastics (MPs) has raised great concerns recently. Plastic mulching has contributed a lot in the building of MP pollution in farmlands. This technique has been in use for decades worldwide because of its immense advantages, preferably in drier and colder regions. The physical extraction of plastic mulches at the end of the growing season is very laborious and ineffective, and thus small pieces of mulches are left in the field which later convert into MP particles after aging, weathering, or on exposure to solar radiation. MPs not only influence physical, chemical, or biological properties of soils but also reduce crop productivity which could be a threat to our food security. They also interact with and accumulate other environmental contaminants such as microbial pathogens, heavy metals, and persistent organic pollutants on their surfaces which increase their risk of toxicity in the environment. MPs also transfer from one trophic level to the other in the food chain and ultimately may impact human health. Because of the ineffectiveness of the recovery of plastic film fragments from fields, researchers are now mainly focusing on alternative solutions to conventional plastic mulch films such as the use of biodegradable mulches. In this review, we have discussed the issue of plastic mulch films in agroecosystems and tried to link already existing knowledge to the current limitations in research on this topic from cropland soils and future prospects have been identified and proposed.

Ameliorative role of foliar Zn-lysine application on wheat (Triticum aestivum L.) stressed by Tannery Wastewater.

Tannery industries discharge a high concentration of chromium (Cr) along with other heavy metals, which are hazardous for all life forms. With increasing shortage of freshwater, tannery effluent is frequently used for crop an irrigation, causing damage to plants' health. In order to address this challenge, amino acid chelate fertilizer was used to investigate the impact on wheat crops against tannery waste water. Tannery wastewater (TW) was used at different levels such as 0%, 25%, 50%, and 100% with an amendment of foliar Zn-lysine (Zn-lys) at30 mg/L. This research highlighted the positive correlation of Zn-lysine on the morpho-physiological, biochemical, and gas exchange traits under different levels of tannery wastewater. The findings of this study showed that the application of Cr-rich tannery wastewater at different treatment levels resulted in a significant reduction in plant height (23%, 31%, and 36%), the number of tillers (21%, 30%, and 43%), spike (19%, 36%, and 55%) and dry weight (DW) of grains (10%, 25%, and 49%) roots DW (17%, 41%, 56%), and shoots DW (22%, 32%, and 47%) as compared to control. Foliar-applied Zn-lys positively enhanced photosynthetic attributes, antioxidant enzymes activities and gas exchange traits by reducing the oxidative stress alone and under Cr stress. The concentration of Cr in roots (21%, 37%, 38%) and shoots (11%, 36%, 37%) was reduced by the foliar application of Zn-lys at different treatment levels. These findings conclude that Zn-lys served as a protector for the growth and development of wheat and has an incredible potential to inhibit the phytotoxicity induced by excess Cr. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-022-01265-6.

Use of Parthenium hysterophorus with synthetic chelator for enhanced uptake of cadmium and lead from contaminated soils-a step toward better public health.

Parthenium hysterophorus L. is a vigorous plant species with cosmopolitan distribution. It can uptake considerable quantities of heavy metals from the soil and accrue these metals in its different tissue. The use of chelating agent i.e., Ethylenediaminetetraacetic acid (EDTA) can boost up metal uptake capacity. Pot experiment was performed to evaluate phytoextraction potential of P. hysterophorus for lead (Pb) and cadmium (Cd) with and without the aid of EDTA chelator. Shoot length, weight of root and shoot (both fresh and dry), leaves number, and chlorophyll contents of P. hysterophorus got reduced with an increase in metal uptake. The results revealed the highest concentration of Cd in shoot without and with EDTA was 283.6 and 300.1 mg kg-1, correspondingly. Increase in Pb concentration was also boosted up by the EDTA from its maximum concentration in shoot 4.30-9.56 mg kg-1. Generally, Pb and Cd concentrations were greater in shoots of P. hysterophorus than the roots regardless of EDTA in the treatments. EDTA also impacted positively the accumulation of essential ions K+, Na+, and Ca+2 in P. hysterophorus. The capacity of P. hysterophorus to accumulate Pb and Cd found to be increased with EDTA in the soil. Bringing metals level in the soil in accordance to the WHO standards can improve the ecosystem as well as public health.

Effects of microplastics on growth and metabolism of rice (Oryza sativa L.).

Present work studied the impact of different doses of polystyrene (PS) and polyvinyl chloride (PVC) microplastics (MPs) on rice plants (Oryza sativa L.). Seven different treatments of PS and PVC MPs viz. D0 (control), D1-D3 (0, 1.5, and 3.0 mg L-1 PS-MP) and D4-D6 (0, 1.5, and 3.0 mg L-1 PVC-MP) were given. In the experiment, sequential variations in growth, ionic homeostasis, and antioxidant metabolism in rice were monitored. Results show that compared to control, maximum repression in shoot and root and fresh and dry weight were recorded in D6. We demonstrate that D3 and D6 reduced the photosynthetic rate up to 31.49 and 43.81% compared to D0 while the transpiration rate was enhanced only under controlled conditions. Water use efficiency and internal CO2 concentration increased due to incremented doses of MPs. Decline in photosynthetic attributes directly corresponded with reduction in SPAD value (34.96%) at D6. Besides, ionic homeostasis was perturbed and concentration of Ca, N, P, and K in root and shoot was imbalanced due to all levels of MPs and D3 and D6 were found most hazardous for these attributes. The resultant oxidative stress caused increment in MDA (49.26 and 138.44%) and H2O2, (66.72 and 125.18%) at D3 and D6, respectively. The maximum increase in SOD (109.08 and 146.08%), POD (232.59 and 289.23%), and CAT (182.65 and 242.89%) was estimated under D3 and D6, respectively as compared to control. Therefore, we concluded that PVC-MPs accumulation is potentially more devastating for rice growth and metabolism than PS-MPs. We recommend further research experimentats not only for translocation but also for tissue-specific retention of different sized MPs in crop plants to completely understand their influence on food safety.

Mitigation of lead toxicity in Vigna radiata genotypes by silver nanoparticles.

Heavy metal (HM) contamination of the soil through anthropogenic activities influences the living systems and drastically impacts food chain. This study examined the application of silver nanoparticles (AgNPs) in two genotypes (G1 and G2) of Mung bean (Vigna radiata) for ameliorating the Pb toxicity. Different doses of Pb (0, 25, 50 µM) were differentially tackled by AgNPs with the aim of ameliorating the plant attributes. Both genotypes displayed statistically significant quantitative and qualitative modulations for Pb tolerance. In G2, the most prominent increase in plant height (43.79%), fresh biomass (49.56%) and total chlorophyll (20%) was observed at L2 (AgNPs 10 mg/L) in comparison with the control. Overall, photosynthetic rate was increased by 26% in G2 at L6 (AgNPs 25 mg/L + Pb 25 µM). In addition, the results presented 78.5% increase in water use efficiency of G2 while G1 experienced a maximum internal CO2 concentration (209.8%) at L8 (Pb 50 µM). AgNPs triggered balanced uptake of minerals and improved growth of Vigna genotypes. 50 µM Pb was most hazardous and caused maximum reduction in growth of Vigna plants along with a significant suppression in photosynthetic activity, increase in MDA (199.7%) in G1 and H2O2 (292.8%) in G2. In comparison to control, maximum superoxide dismutase (376%), peroxidase (659.8%) and catalase (9.3%) activity was observed in G2 at L11. The application of AgNPs substantially enhanced plant growth and helped them in surviving well in absence as well as presence of Pb. G2 genotype exhibited substantial tolerance capability and revealed less impairment in the studied attributes than G1 and treatment of AgNPs i.e. 25 mg/L was the best level that yielded best results in both genotypes. The results demonstrate that AgNPs mediate response(s) of plants under Pb stress and particularly contributed to HM tolerance of plants and thus showing great promise for use in phytoremediation.