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.

Evaluation of heavy metal accumulation and tolerance in oxalic acid-treated Phragmites australis wetlands for textile effluent remediation.

Water contamination with metals poses significant environmental challenges. The occurrence of heavy metals (HMs) prompts modifications in plant structures, emphasizing the necessity of employing focused safeguarding measures. Cadmium (Cd), lead (Pb), and chromium (Cr) emerge as particularly menacing toxins due to their high accumulation potential. Increasing the availability of organic acids is crucial for optimizing toxic metal removal via phytoremediation. This constructed wetland system (CWs) was used to determine how oxalic acid (OA) treatments of textile wastewater (WW) effluents affected morpho-physiological characteristics, antioxidant enzyme activity, oxidative stress, and HM concentrations in Phragmites australis. Multiple treatments, comprising the application of OA at a concentration of 10 mM and WW at different dilutions (25%, 50%, 75%, and 100%), were employed, with three replications of each treatment. WW stress decreased chlorophyll and carotenoid content, and concurrently enhanced HMs adsorption and antioxidant enzyme activities. Furthermore, the application of WW was found to elevate oxidative stress levels, whereas the presence of OA concurrently mitigated this oxidative stress. Similarly, WW negatively affected soil-plant analysis development (SPAD) and the total soluble proteins (SP) in both roots and shoots. Conversely, these parameters showed improvement with OA treatments. P. australis showed the potential to enhance HM accumulation under 100% WW stress. Specifically, there is an increase in root SP ranging from 9% to 39%, an increase in shoot SP from 6% to 91%, and an elevation in SPAD values from 4% to 64% compared to their respective treatments lacking OA inclusion. The OA addition resulted in decreased EL contents in the root and shoot by 10%-19% and 13%-15%, MDA by 9%-14% and 9%-20%, and H2O2 by 14%-21% and 9%-17%, in comparison to the respective treatments without OA. Interestingly, the findings further revealed that the augmentation of OA also contributed to an increased accumulation of Cr, Cd, and Pb. Specifically, at 100% WW with OA (10 mM), the concentrations of Cr, Pb, and Cd in leaves rose by 164%, 447%, and 350%, in stems by 213%, 247%, and 219%, and in roots by 155%, 238%, and 195%, respectively. The chelating agent oxalic acid effectively alleviated plant toxicity induced by toxins. Overall, our findings demonstrate the remarkable tolerance of P. australis to elevated concentrations of WW stress, positioning it as an eco-friendly candidate for industrial effluent remediation. This plant exhibits efficacy in restoring contaminants present in textile effluents, and notably, oxalic acid emerges as a promising agent for the phytoextraction of HMs.

HMs stress decreased the physiology and morphology of Phragmites australis L.OA improved the photosynthetic pigments and antioxidant enzymesHMs accumulation and bioavailability increased under OAPhragmites australis L. showed higher efficacy for textile effluent treatment under OA.

Elucidating the phytoremediation potentials and ecophysiological mechanisms of indicator plants in the industrial polluted region.

The integrity of natural ecosystems, particularly in the Global South, is increasingly compromised by industrial contaminants. Our study examines the growth of plant species adapted to ecosystems impacted by heavy metal pollution, specifically focusing on their phytoremediation capabilities and tolerance to contaminants. The potential of pollution-tolerant species was evaluated in the industrial subtropical wetland of Sialkot, Pakistan. Employing quantitative ecological methods, data on vegetation, phytosociological attributes, and soil properties were gathered from 450 plots across different pollution gradients. The study pinpointed 17 key indicator species tolerating high heavy metal pollution out of 182 surveyed, using a combination of Indicator Species Analysis (ISA) and the Importance Value Index (IVI). These species demonstrated diverse capacities to extract, stabilize, and accumulate heavy metals (Cr, Zn, Cu, As, Cd, Ni, Hg, and Pb) across varying pollution zones. Notably, Cannabis sativa demonstrated substantial phytoextraction of Zn and Cd, with concentrations reaching 1977.25 µg/g and 1362.78 µg/g, respectively. Arundo donax showed marked hyperaccumulation of Cd, peaking at 410.531 µg/g. Achyranthes aspera was remarkable for its extraction and accumulation of Ni and Cu, with concentrations of 242.412 µg/g and 77.2997 µg/g, respectively. Physiological changes, such as increased proline levels in Cannabis sativa and Achyranthes aspera reaching 39.041 µg/g and 27.523 µg/g under high metal concentrations, indicated adaptation to metal stress. Declines in chlorophyll and carotenoid levels were also observed as metal contamination increased, with up to 35% reductions in some species. These findings underscore the potential efficacy of selected plant species in phytoremediation and highlight the importance of physiological responses in their tolerance to metals, providing valuable information for targeted remediation strategies in polluted ecosystems and improving environmental management and sustainable practices.

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.

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.

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.

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.

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.

Spike glycoproteins: Their significance for corona viruses and receptor binding activities for pathogenesis and viral survival.

The recent outbreak of Covid-19 is posing a severe threat to public health globally. Coronaviruses (CoVs) are the largest known group of positive-sense RNA viruses surviving on an extensive number of natural hosts. CoVs are enveloped and non-segmented viruses with a size between 80 and 120 nm. CoV attachment to the surface receptor and its subsequent entrance into cells is mediated by Spike glycoprotein (S). For enhanced CoV entry and successful pathogenesis of CoV, proteolytic processing and receptor-binding act synergistically for induction of large-scale S conformational changes. The shape, size and orientation of receptor-binding domains in viral attachment proteins are well conserved among viruses of different classes that utilize the same receptor. Therefore, investigations unraveling the distribution of cellular receptors with respect to CoV entry, structural aspects of glycoproteins and related conformational changes are highly significant for understanding virus invasion and infection spread. We present the characteristic features of CoV S-Proteins, their significance for CoVs and related receptor binding activities for pathogenesis and viral survival. We are analyzing the novel role of S-protein of CoVs along with their interactive receptors for improving host immunity and decreasing infection spread. This is hoped that presented information will open new ways in tackling coronavirus, especially for the ongoing epidemic.

Assessment of Lead and Cadmium Pollution in Soil and Wild Plants at Different Functional Areas of Sialkot.

Heavy metal pollution is a great hazard to the environment that enters the ecosystem through different natural and anthropogenic sources. A study was performed to evaluate concentrations of Cd and Pb in selected plants, Ricinus communis and Parthenium hysterophorus, and soils from different functional sites in Sialkot. Maximum fresh and dry weights of R. communis were recorded from control and field sites. Highest concentrations of Cd in P. hysterophorus (33.5 mg kg-1) and R. communis (24.36 ± 2.83 mg kg-1) were recorded at residential and industrial sites, respectively. However, road site samples showed maximum concentrations of Pb both in R. communis (9.06 ± 0.35 mg kg-1) and P. hysterophorus (7.90 ± 0.36 mg kg-1). Soil from the road site were found to be highly acidic (pH 4.75 ± 0.04), while the field site showed highest EC (494 ± 3.60) and TDS (509 ± 3.00) values. Generally, there were reductions in chlorophyll a and carotenoids, but an increase in chlorophyll b was observed in both plants at all sites compared to the control.

Rising Metals Concentration in the Environment: A Response to Effluents of Leather Industries in Sialkot.

Many leather processing industries in Sialkot, Pakistan, discharge their wastes freely into the environment which then enters nearby water bodies. Irrigation practices with these polluted waters pose a great threat to the soil quality. Hence, the soils and effluent waters of five famous leather processing sites were evaluated for the presence of As, Cr, Cd, Ni, Zn, Mn, Mg, Na, K, and Ca. High mean concentrations of As (112.6 mg kg-1), Cr (45.9 mg kg-1), Cd (2.0 mg kg-1), Ni (58.2 mg kg-1), Zn (117.6 mg kg-1), Mn (12.8 mg kg-1), Mg (34,511 mg kg-1), Na (16,292 mg kg-1), K (1765 mg kg-1), and Ca (4387 mg kg-1) were found in soils at our study sites. Effluents were found to be highly acidic with high TDS content and high EC values. Index of Geoaccumulation (Igeo) confirmed the extremely toxic nature of these soils. Plants growing at these sites also showed high concentrations of As, Cr, and Cd in their leaves.

Zinc finger protein transcription factors: Integrated line of action for plant antimicrobial activity.

The plants resist/tolerate unfavorable conditions in their natural habitats by using different but aligned and integrated defense mechanisms. Such defense responses include not only morphological and physiological adaptations but also the genomic and transcriptomic reconfiguration. Microbial attack on plants activates multiple pro-survival pathways such as transcriptional reprogramming, hypersensitive response (HR), antioxidant defense system and metabolic remodeling. Up-regulation of these processes during biotic stress conditions directly relates with plant survival. Over the years, hundreds of plant transcription factors (TFs) belonging to diverse families have been identified. Zinc finger protein (ZFP) TFs have crucial role in phytohormone response, plant growth and development, stress tolerance, transcriptional regulation, RNA binding and protein-protein interactions. Recent research progress has revealed regulatory and biological functions of ZFPs in incrementing plant resistance to pathogens. Integration of transcriptional activity with metabolic modulations has miniaturized plant innate immunity. However, the precise roles of different zinc finger TFs in plant immunity to pathogens have not been thoroughly analyzed. This review consolidates the pivotal functioning of zinc finger TFs and proposes the integrative understanding as foundation for the plant growth and development including the stress responses.

Lead Concentrations in Soils and Some Wild Plant Species Along Two Busy Roads in Pakistan.

This study assessed the level of Pb in soil and five wild plant species (Calotropis procera, Datura alba, Parthenium hysterophorus, Cenchrus ciliaris and Ricinus communis) during all the four seasons. Two busy roads varying in age and traffic volume were selected i.e., Faisalabad-Sargodha road (FSR) and Pindi Bhattian to Lillah (M-2) in the Punjab, Pakistan. Results showed raised levels of Pb in both plants and soil samples along both roads. The range of Pb concentration in plants was 0.08-3.98 and 1.95-4.74 mg kg- 1 for soil. Higher Pb contamination was recorded along FSR road as compared to M-2. Among seasons, the higher Pb concentration was found during summer, probably due to very high temperature. Among all the plants studied, Calotropis procera accumulated the highest level (3.98 mg kg- 1 dry wt.) of Pb; Thus, it can be used as good biomonitor/phytoremediator at Pb contaminated areas.

Synthesis, spectral characterization and enzyme inhibition studies of different chlorinated sulfonamides.

Sulfonamides are adherent to a biologically dynamic category of compounds and are under consideration of many organic synthetic researches to synthesize pharmacologically important compounds. In this demonstrated research work, a benignant series of chlorinated sulfonamides were synthesized and screened against different enzymes. These various chlorinated sulfonamides (3a-i) were set up by pairing of different substituted anilines (2a-i) with 4-chlorobenzenesulfonyl chloride (1) under basic pH in an aqueous media. The structures of the synthesized chlorinated sulfonamides were furnished by 1H-NMR, IR & EI-MS. The different enzymes used for the evaluation of bioactivity of all the synthesized compounds were urease, butyrylcholinesterase (BChE) and lipoxygenase (LOX). All the compounds exhibited good inhibitory activities against these enzymes but the strong activity was shown against BChE and hence can be employed for discovery of 'lead' compounds against Alzheimer's disease (AD).

Synthesis, characterization and enzyme inhibition study of O-substituted derivatives of chlorinated coumarin.

Coumarins have much importance in dyes, drugs, perfumes and pesticides. In the demonstrated research work, a benignant series of chlorinated coumarins was synthesized and screened against different enzymes. First, 6-Chloro-7-hydroxy-4-methyl-2H-chromen-2-one (3) was geared up by the reaction of 4-chlororesorcinol (1) and ethyl acetoacetate (2) in the presence of concentrated H(2)SO(4). Second, various O-substituted derivatives of chlorinated coumarins, 5a-j, were set up by pairing different alkyl/aralkyl halides, 4a-j, with 3 in the presence of NaH in DMF as solvent. The structures of all the synthesized compounds were clarified through spectral analysis using EI-MS, IR and (1)H-NMR. The different enzymes used for the evaluation of bioactivity of all the synthesized compounds were acetyl cholinesterase (AChE), butyryl cholinesterase (BChE) and lipoxygenase (LOX). The most proficient activity was shown against both cholinesterase enzymes.

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.

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.

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.