Search Results (84)

Soil salinization remains a critical constraint on global land sustainability, severely limiting agricultural output and ecosystem resilience. To address this issue, a field trial was implemented to investigate the interactive benefits of vermicompost (VC) and a novel soil conditioner derived from coal gasification slag-based soil conditioner (CGSS) in mitigating saline–alkali stress. The perennial forage grass Leymus chinensis, valued for its ecological robustness and economic potential under adverse soil conditions, served as the test species. Five treatments were established: CK (unamended), T1 (CGSS alone), T2 (VC alone), T3 (CGSS:VC = 1:1), T4 (CGSS:VC = 1:2), and T5 (CGSS:VC = 2:1). Study results indicate that the combined application of CGSS and VC outperformed individual amendments, with the T4 treatment demonstrating the most effective results. Compared to CK, T4 reduced soil electrical conductivity (EC) by 12.00% and pH by 5.17% (p < 0.05), while markedly enhancing key fertility indicators—including soil organic matter and the availability of nitrogen, phosphorus, and potassium. Thus, these improvements translated into superior growth of L. chinensis, reflected in significantly greater dry biomass, expanded leaf area, and increased plant height. Additionally, the T4 treatment increased soil microbial richness (Chao1 index) by 21.5% and elevated the relative abundance of the Acidobacteria functional group by 16.9% (p < 0.05). Hence, T4 treatment (CGSS: 15,000 kg·ha⁻¹; VC: 30,000 kg·ha⁻¹) was identified as the optimal remediation strategy through a fuzzy comprehensive evaluation that integrated multiple soil and plant indicators. From an economic perspective, the T4 treatment (corresponding to a VC-CGSS application ratio of 2: 1) exhibits a lower cost compared to other similar soil conditioners and organic fertilizer combinations for saline–alkali soil remediation. This study not only offers a practical and economically viable approach for reclaiming degraded saline–alkali soils but also advances the circular utilization of coal-based solid waste. Furthermore, it deepens our understanding of how integrated soil amendments modulate the soil–microbe–plant nexus under abiotic stress. Full article

The present study systematically explored the purification effects and response of submerged plants, Ceratophyllum demersum and Myriophyllum spicatum, on toxic and non-toxic strains of Microcystis aeruginosa via indoor co-culture experiments. The results showed that: (1) Both plants significantly inhibited the growth of Microcystis and reduced the concentration of chlorophyll-a (Chla) in the water by rapidly absorbing nutrients such as nitrogen and phosphorus, with no significant differences in the inhibition between toxic and non-toxic strains, indicating that nutrient competition might be the dominant mechanism for algal suppression. (2) C. demersum had higher nitrogen and phosphorus removal efficiency than M. spicatum, but the microcystins (MCs) released by toxic M. aeruginosa inhibited the nutrient removal capacity of both plants. (3) The plants promoted cell lysis of toxic M. aeruginosa and reduced extracellular MCs in the water while accumulating MCs internally, with C. demersum showing stronger MC accumulation and removal ability. (4) Microcystis stress activated the plants’ antioxidant defense systems, increased activities of SOD (Superoxide Dismutase) and CAT (Catalase), and caused membrane lipid peroxidation, increased content of MDA (Malondialdehyde), with toxic M. aeruginosa inducing stronger oxidative stress, and M. spicatum being more severely affected. (5) Plant species and algal toxicity jointly drove changes in the attached microbial community structure. The rhizosphere of M. spicatum specifically enriched Bdellovibrionota, suggesting a potential microbial predation pathway for algal suppression, while C. demersum was more associated with Bacillus and other microbes with allelopathic potential. In summary, C. demersum performed better in nutrient removal, toxin accumulation, and physiological tolerance. This study provides further theoretical support for using submerged plants to regulate cyanobacterial blooms and remediate eutrophic water bodies. Full article

Soil co-contamination with heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) represents a widespread and challenging environmental issue that is difficult to address using conventional remediation methods. This review systematically examines the molecular mechanisms by which plant root exudates mediate the remediation of co-contaminated soils through synergistic interactions with rhizosphere microorganisms. We detail how plants dynamically adjust the composition and secretion of root exudates—such as organic acids, amino acids, sugars, and secondary metabolites—in response to combined HM-PAH stress. These exudates play multifaceted roles in remediation, including chelating HMs, enhancing PAH solubility and bioavailability, and acting as chemoattractants and metabolic substrates for rhizosphere microbes. In return, the recruited microbial communities contribute to pollutant detoxification through various mechanisms, such as biosurfactant production, enzymatic degradation, and improved plant nutrient acquisition. This reciprocal interaction forms a synergistic plant-microbe feedback loop that effectively mitigates combined contamination stress. By integrating evidence from diverse plant–soil systems, this review provides a comprehensive mechanistic framework for understanding root exudate-microbe interactions, offering critical insights for developing enhanced phytoremediation strategies to address complex environmental pollution. Full article

Straw return is a potential practice for adsorbing salt and retaining moisture in saline–alkali soils. However, adverse climate conditions such as prolonged drought and cold winters shorten the effective structural turnover of returned straw biomass in soils. Furthermore, the rigid crystalline cell walls and recalcitrant lignin components of undecomposed plant residues lower the adsorption capacity towards salt. Here, we report the pretreatment of neutral oxalic acid to destroy the dense crystalline structure of cotton straw cellulose. Through laboratory experiments, combined with the changes in the structural and chemical properties of cotton straw, the optimal oxalic acid pretreatment (OAC) conditions were determined. Subsequently, the application effectiveness of OAC was evaluated via pot experiments and field trials. The optimal conditions of OAC were 0.2% dosage, 60 °C, and 24 h, displaying a maximum increase in salt absorption and water retention capacities of cotton straw materials, through exposing the hydroxyl network of cellulose and chemically hydrolyzing recalcitrant lignin. In the indoor potted plant experiments, the feasible application of oxalic acid pretreatment can be regarded as an active barrier, increasing soil moisture by 16–43% and reducing total salts by 23–26% in the topsoil (0–20 cm) within a 45-day laboratory incubation. Additionally, the OAC pretreatment had negligible adverse impacts on soil microbial communities. Moreover, some plant-beneficial microbes (e.g., Sphingomonadaceae and Gemmatimonadaceae) were stimulated, with their relative abundance increasing by 26–40% and 27–63%, respectively. Ultimately, under the pretreatment of oxalic acid-modified cotton straw salt-absorbing water-retention agent (OAC-SR), cotton seedling emergence rates, plant height, and biomass all increased to varying degrees across different concentrations of saline–alkali soil (0.05–1.0%) in the field. Then OAC-SR can be potentially applied to the process of cotton straw return to facilitate the turnover of straw structure in soil, enhance the salt-adsorption and water-retention capacities of returned straw, and provide a low-salt microenvironment for crop growth. This study demonstrates a further low-carbon and in situ applicable route to accelerate the destruction of cotton straw structure, thereby alleviating crop salt damage and promoting the green circular development of saline–alkali soil remediation. Full article

Soil degradation and pollution pose significant threats to global agricultural sustainability and food security. Conventional remediation methods are often constrained by low efficiency, high cost, and potential secondary pollution. Nanobiotechnology, an emerging interdisciplinary field, offers innovative solutions by integrating functional nanomaterials with plant–microbe interactions to advance soil remediation and sustainable agriculture. This review systematically elaborates on the mechanisms and applications of nanomaterials in soil remediation and enhanced plant stress resilience. For contaminant removal, nanomaterials such as nano-zero-valent iron (nZVI) and carbon nanotubes effectively immobilize or degrade heavy metals and organic pollutants through adsorption, catalysis, and other reactive mechanisms. In agriculture, nanofertilizers facilitate the regulated release of nutrients, thereby markedly enhancing nutrient use efficiency. Concurrently, certain nanoparticles mitigate a range of abiotic stresses—such as drought, salinity, and heavy metal toxicity—through the regulation of phytohormone balance, augmentation of photosynthetic performance, and reinforcement of antioxidant defenses. However, concerns regarding the environmental behavior, ecotoxicity, and long-term safety of nanomaterials remain. Future research should prioritize the development of smart, responsive nanosystems, elucidate the complex interactions among nanomaterials, plants, and microbes, and establish comprehensive life-cycle assessment and standardized risk evaluation frameworks. These efforts are essential to ensuring the safe and scalable application of nanobiotechnology in environmental remediation and green agriculture. Full article

Heavy metal (HM) contamination in agricultural soils poses a significant threat to soil health and plant productivity. This study investigates the impact of cadmium (Cd) and zinc (Zn) stress on tomato plants (Solanum lycopersicum) and explores the mitigation potential of microbial biostimulants (MBs), including arbuscular mycorrhizal fungi (AMF) and Pseudomonas fluorescens So_08 (PGPR), over a 52-day period using multi-omics approaches. Root exudate profiling revealed distinct metabolic changes under HM stress, which compromised soil–plant interactions. Cd stress reduced the secretion of phenylpropanoids (sum LogFC: −45.18), lipids (sum LogFC: −27.67), and isoprenoids (sum LogFC: −11–67), key metabolites in antioxidative defense, while also suppressing rhizosphere fungal populations. Conversely, Zn stress enhanced lipid exudation (such as sphingolipids and sterols, as sum LogFC of 8.72 and 9.99, respectively) to maintain membrane integrity and reshaped rhizobacterial communities. The MBs application mitigated HM-induced stress by enhancing specialized metabolite syntheses, including cinnamic acids, terpenoids, and flavonoids, which promoted crop resilience. MBs also reshaped microbial diversity, fostering beneficial species like Portibacter spp., Alkalitalea saponilacus under Cd stress, and stimulating rhizobacteria like Aggregatilinea spp. under Zn stress. Specifically, under Cd stress, bacterial diversity remained relatively stable, suggesting their resilience to Cd. However, fungal communities exhibited greater sensitivity, with a decline in diversity in Cd-treated soils and partial recovery when MBs were applied. Conversely, Zn stress caused decline in bacterial α-diversity, while fungal diversity was maintained, indicating that Zn acts as an ecological filter that suppresses sensitive bacterial taxa and favors Zn-tolerant fungal species. Multi-omics data integration combined with network analysis highlighted key features associated with improved nutrient availability and reduced HM toxicity under MB treatments, including metabolites and microbial taxa linked to sulfur cycling, nitrogen metabolism, and iron reduction pathways. These findings demonstrate that MBs can modulate plant metabolic responses and restore rhizosphere microbial communities under Cd and Zn stress, with PGPR showing broader metabolomic recovery effects and AMF influencing specific metabolite pathways. This study provides new insights into plant–microbe interactions in HM-contaminated environments, supporting the potential application of biostimulants for sustainable soil remediation and plant health improvement. Full article

As a typical heavy metal pollutant, cadmium (Cd) poses significant threats to ecosystems and human health. Giant duckweed (Spirodela polyrhiza), a small aquatic plant characterized by rapid growth and efficient heavy metal accumulation, holds great promise for phytoremediation. However, the mechanisms by which S. polyrhiza enriches Cd—particularly the contributions of its surface-associated microbiota—remain poorly understood. In this study, S. polyrhiza fronds were exposed to 0, 1, and 10 μM Cd, and we observed a concentration-dependent increase in the abundance of epiphytic microorganisms on the frond surfaces. High-throughput 16S rRNA gene sequencing revealed that Cd stress significantly altered the diversity of the frond-epiphytic bacterial community. Notably, the relative abundances of the genera Herbaspirillum, Enterobacter, and Pantoea increased significantly with rising Cd concentrations. Functional prediction using PICRUSt2 indicated enrichment under Cd stress of specific traits—such as the nitrate/nitrite transporter NarK, signal transduction mechanisms, and ion channel proteins—suggesting these taxa may actively participate in Cd uptake and tolerance. Together, our results reveal a synergistic S. polyrhiza–microbiome response to Cd and identify taxa/functions as targets and biomarkers for microbe-augmented remediation. Full article

Environmental dissemination of antibiotics is a pressing global challenge, driving ecological imbalances and the proliferation of antibiotic resistance genes (ARGs). Conventional treatment technologies often fail to fully eliminate these micropollutants or are cost-prohibitive for widespread use. In this context, phytoremediation—using plants and their associated microbiota to remove, transform, or immobilize contaminants—has emerged as an effective and promising, low-impact, and nature-based approach for mitigating antibiotic pollution in aquatic and terrestrial environments. This review provides a comprehensive synthesis of the physiological, biochemical, and ecological mechanisms by which plants interact with antibiotics, including phytoextraction, phytodegradation, rhizodegradation, and phytostabilization. This review prioritizes phytoremediation goals, with attention to high-performing aquatic (e.g., Lemna minor, Eichhornia crassipes, Phragmites australis) and terrestrial plants (e.g., Brassica juncea, Zea mays) and their ability to remediate major classes of antibiotics. This study highlights the role of rhizosphere microbes and engineered systems in phytoremediation, while noting challenges such as variable efficiency, phytotoxicity risks, limited knowledge of by-products, and environmental concerns with antibiotic degradation. Future perspectives include the integration of genetic engineering, microbiome optimization, and smart monitoring technologies to enhance system performance and scalability. Plant-based solutions thus represent a vital component of next-generation remediation strategies aimed at reducing antibiotic burdens in the environment and curbing the rise in antimicrobial resistance. Full article

Soil lead (Pb) contamination poses a severe threat to agricultural sustainability and food security. Phytoremediation offers a green alternative for remediation, yet its efficiency is limited by poor plant tolerance and restricted metal uptake. In this study we investigated the functional roles of the microbial inoculants Trichoderma guizhouense NJAU4742 and Bacillus velezensis SQR9 in enhancing the performance of Salix suchowensis P1024 grown in Pb-contaminated soil. NJAU4742 significantly increased plant biomass by 34% (p < 0.05), accompanied by increased soil microbial biomass and higher activities of urease, acid phosphatase, and sucrase. In contrast, SQR9 strongly enhanced Pb accumulation by 19% (p < 0.05), which was accompanied by upregulated antioxidant enzymes, reduced lipid peroxidation, and elevated cysteine levels. Random forest and correlation analyses demonstrated that soil nutrient cycling indices (urease, MBC, sucrase) were key predictors of biomass, whereas antioxidant defenses (POD, CAT) primarily explained Pb accumulation. These findings provide new insights into the distinct contributions of NJAU4742 and SQR9 to willow growth and Pb remediation, and provide a basis for developing more effective microbe-assisted phytoremediation strategies. Full article

Cadmium (Cd) contamination of soil threatens agricultural productivity and food safety. In this study, a dual-component remediation strategy combining lanthanum-cysteine chelate (CLa) and corn steep liquor (CSL) was developed to alleviate Cd toxicity in Chinese cabbage (Brassica rapa subsp. pekinensis). CLa enhanced photosynthetic efficiency, antioxidant enzyme activity, and root viability, while reducing Cd translocation to shoots. In contrast, CSL acted primarily through organic nutrient supplementation, stimulating chlorophyll synthesis and promoting the growth of beneficial rhizosphere microbes. Notably, the combined treatment (CLCS) exhibited a synergistic effect, significantly enhancing biomass production, nutrient uptake, photosynthetic performance, and oxidative stress tolerance, while reducing Cd accumulation in plant tissues. Furthermore, CLCS optimized the soil microenvironment and microbiota composition, reinforcing plant resilience under Cd stress. This study offers a promising and cost-effective approach for mitigation of heavy metal stress and crop productivity improvement by coordinated plant–microbe–soil interactions. Full article

Soil contamination in industrial areas often involves complex mixtures of contaminants, making remediation a significant challenge. Microbe-assisted phytoremediation offers a promising solution, yet its success depends on understanding interaction between plants, microorganisms, and contaminants in rhizosphere. This study examined the effects of organic (oil sludge) and inorganic (Zn) contaminants, applied individually and in combination, on the rhizosphere bacterial community of Miscanthus × giganteus Greef et Deu (M×g), with emphasis on strains exhibiting plant growth-promoting, hydrocarbon-degrading, and metal-tolerant traits. A one-season greenhouse experiment included soils spiked with Zn (1650 mg kg⁻¹) and/or oil sludge (15 mL kg⁻¹). Oil sludge exerted a stronger influence on the taxonomic structure of rhizobacterial communities than Zn, largely shaping the patterns observed under co-contamination. Zn exposure increased the relative abundance of Actinobacteriota, whereas oil sludge favoured Proteobacteriota. Both contaminants, individually and together, enhanced the proportion of Sphingomonadaceae. Across all treatments, taxa with potential plant-growth-promoting traits were present, while co-contaminated soil harboured microorganisms capable of hydrocarbon degradation, heavy metal tolerance, and plant growth promotion. These findings highlight the adaptive capacity of the M×g rhizobiome and support its application in phytoremediation. The isolation and characterisation of rhizosphere-associated strains provide basis for developing microbial bioagents to enhance biomass production and remediation efficiency in multi-contaminated environments. Full article

Investigating the microbial community structure and stress-tolerance mechanisms in the rhizospheres of salt-adapted plants along saline lakes is critical for understanding plant–microbe interactions in extreme environments and developing effective strategies for saline–alkaline soil remediation. This study explored the rhizosphere microbiomes of four salt-adapted species (Suaeda glauca, Artemisia carvifolia, Chloris virgata, and Limonium bicolor) from the Yuncheng Salt Lake region in China using high-throughput sequencing. Cultivable salt-tolerant plant growth-promoting rhizobacteria (PGPR) were isolated and characterized to identify functional genes related to stress resistance. Results revealed that plant identity and soil physicochemical properties jointly shaped the microbial community composition, with total organic carbon being a dominant driver explaining 17.6% of the variation. Cyanobacteria dominated low-salinity environments, while Firmicutes thrived in high-salinity niches. Isolated PGPR strains exhibited tolerance up to 15% salinity and harbored genes associated with heat (htpX), osmotic stress (otsA), oxidative stress (katE), and UV radiation (uvrA). Notably, Peribacillus and Isoptericola strains demonstrated broad functional versatility and robust halotolerance. Our findings highlight that TOC (total organic carbon) plays a pivotal role in microbial assembly under extreme salinity, surpassing host genetic influences. The identified PGPR strains, with their stress-resistance traits and functional gene repertoires, hold significant promise for biotechnological applications in saline–alkaline soil remediation and sustainable agriculture. Full article

Soil salinization poses a critical threat to global agriculture, necessitating innovative strategies for sustainable remediation. This review synthesizes advances in leveraging plant–microbe interactions to remediate saline–alkali soils, focusing on oilseed crops—Brassica napus, Glycine max, Arachis hypogaea, Helianthus annuus, and Sesamum indicum—as keystone species for ecosystem restoration. These crops exhibit unique adaptive strategies, including root architectural plasticity and exudate-mediated recruitment of stress-resilient microbiomes (Proteobacteria, Actinobacteria, and Ascomycota), which collectively stabilize soil structure and enhance nutrient cycling, ion homeostasis, and soil aggregation to mitigate soil salinity and alkalinity. Emerging technologies further amplify these natural synergies: nanomaterials optimize nutrient delivery and microbial colonization, while artificial intelligence (AI) models predict optimal plant growth-promoting rhizobacteria (PGPR) combinations and simulate remediation outcomes. This integration establishes a roadmap for precision microbiome engineering, offering scalable strategies to restore soil health and ensure food security in saline–alkali ecosystems. Full article

Biochar has demonstrated effectiveness in environmental remediation. However, the physicochemical properties of biochar change with natural aging, which potentially impacts its efficacy. This study was designed to evaluate the effects of aged biochar (at 1% and 5% rates) on the growth of Chinese cabbage, greenhouse gas emission, and Cd remediation in soils. Canada goldenrod (Solidago canadensis L.) feedstock biochar was subjected to three artificial aging processes (freeze–thaw cycle, dry–wet cycle, and hydrogen peroxide oxidation) to prepare aged biochar. Results showed that aging significantly altered properties and structure of biochar. Biochar addition had no effect on CH₄ emissions, but it decreased cumulative N₂O emission (all treatments) and increased cumulative CO₂ emission (only the pristine biochar at 5% application rate). Aged biochar showed no effect on microbial life strategy and Shannon index. However, PB-5% application shifted the life history strategies of A-strategists (resource acquisition microbe) towards Y-strategists (high-yield microbe) such as Proteobacteria, Gemmatimonadota, Bacteroidota, Firmicutes and Actinobacteriota, which partially attributed to the enhanced soil CO₂ emission. Aged biochar reduced plant uptake Cd and soil available Cd concentrations by up to 36.6% and 34.0%, respectively, ascribing to improved soil physicochemical properties and functional bacterial abundance. Full article

The management and use of saline–alkaline land is a global concern and research focus. Although there is extensive long-term global research on soil salinization and improvement, systematic summaries of research progress in this field are insufficient. This study, based on the Web of Science (WOS) and incoPat database, analyzes the literature and patents on saline–alkaline land over the past 30 years, sums up research progress and current status, and proposes future directions to lay a foundation for further study. Research hotspots are mainly salt-tolerant plant growth mechanisms and gene expression under salt stress, interactions between salt-tolerant plants and microbes, soil conditioner use, remote sensing monitoring of saline–alkaline land changes, irrigation and drainage techniques, and soil nutrient status and improvement. Saline–alkaline land management research is moving toward integrated application of multiple improvement measures. Priority should be given to developing land remediation technologies and salt-tolerant plant varieties suited to different regions; studying the compatibility among technologies, plant varieties, and cultivation techniques; establishing region- and type-specific integrated management and ecological use methods; and creating comprehensive development plans to boost soil productivity and protect the ecology. Full article