Abstract Interest in bio-based herbicides, such as pelargonic acid (PA), a naturally occurring fatty acid with rapid post-emergent herbicidal activity, has increased in response to the growing demand for sustainable and effective weed-control strategies. However, its practical application remains constrained by high volatility, photodegradation, and limited residual activity. In this study, kraft lignin (KL) was fractionated using aqueous acetic acid at defined concentrations (30%, 40%, and 50%) to obtain well-characterized fractions (KL30, KL40, and KL50). These fractions were subsequently used to synthesize lignin nanoparticles encapsulating PA via antisolvent precipitation. The resulting formulations were systematically characterized for their structural, colloidal, and thermal properties, as well as photostability, release kinetics, and herbicidal performance. Among the tested systems, KL30-based nanoparticles demonstrated high encapsulation efficiency, enhanced resistance to ultraviolet C radiation, and sustained colloidal stability. Post-emergence bioassays using Lolium multiflorum and Amaranthus viridis demonstrated that KL30_1PA induced rapid and severe phytotoxicity effects like those of commercial formulations while also maintaining low cytotoxicity toward mammalian cells. These findings demonstrate that rational lignin fractionation improves nanoparticle design and supports the development of scalable, effective, and environmentally sustainable agrochemical delivery systems for PA.
Abstract Halophytes are plants uniquely adapted to saline environments and offer potential applications in the food industry. This study evaluates the perennial halophyte Salicornia perennis as a source of lipophilic compounds with nutritional relevance. The lipophilic profile of S. perennis, collected from three distinct salt marshes in Portugal, was established to uncover its nutritional potential. Lipophilic constituents were extracted and analyzed using gas chromatography-mass spectrometry. An integrated relative stress level, based on sedimentary and hydrodynamic conditions, characterized the environmental context of each sampling site. Statistical analyses revealed significant variation in the chemical profile across sites, highlighting the capacity of S. perennis to adjust its nutritional composition to different salt-marsh microhabitats. These results indicate biochemical plasticity in response to distinct salt-marsh microhabitats. At the lower-stress, sandy, better-drained Mira microhabitat, plants accumulated higher concentrations of unsaturated fatty acids, sterols, and fatty alcohols. In contrast, the more waterlogged, clay-rich Ílhavo microhabitat showed higher levels of sugars and saturated lipids, whereas São Jacinto showed a distinct profile enriched in small organic acids and β-sitosterol. These findings support the potential of S. perennis as an edible halophyte and candidate crop for saline agriculture, while showing that local sedimentary and hydrodynamic conditions modulate its lipophilic nutritional profile.
Abstract Copper (Cu) and sulfur (S)-based compounds have long been used in agriculture, yet their conventional soluble formulations often require repeated application and can contribute to off-target environmental loading. In recent years, nanoforms of Cu and S have been explored as alternative agricultural materials due to their reactivity, release kinetics, and biological interactions, which can differ markedly from those of bulk or ionic counterparts. Building on this progress, this review examines the potential of copper sulfide nanoparticles (CuS NPs) as an emerging material that integrates micronutrient chemistry, redox activity, and nanoscale functionality. The number of studies directly evaluating CuS NPs in agriculture remains relatively limited, but existing reports suggest three main application pathways: as antifungal/antibacterial agents, as nanocarriers for pesticidal active ingredients, and as controlled nutrient-delivery platforms for plant-relevant elements. Several studies have reported promising agronomic performance of CuS NPs compared to Cu-containing NPs and synthetic pesticides. However, results are highly context dependent. This review identifies key gaps in benchmarking, mechanistic validation, and fate assessment under realistic soil–plant exposure scenarios. Such studies are required to strategically design and assess CuS formulations that will deliver tangible agronomic benefits without unacceptable environmental risks.
Abstract Two environmentally friendly iron-functionalized pine-wood-derived biochar adsorbents were developed and compared for phosphate recovery and reuse: (i) ferric chloride-modified biochar (Fe-BC) and (ii) green tea–mediated iron-modified biochar (GT-Fe-BC). Batch experiments demonstrated effective phosphate recovery by Fe-BC (>80%) and GT-Fe-BC (>70%) within ∼1 h. Adsorption kinetics for both materials were best described by the pseudo-second-order (PSO) model, indicating a chemisorption-dominated process. Elovich and intraparticle diffusion analyses further confirmed that phosphate uptake involved chemisorption accompanied by both film diffusion and intraparticle diffusion. Freundlich isotherm fitting indicated heterogeneous surface adsorption for both materials, with GT-Fe-BC exhibiting a broader distribution of active sites. The maximum P adsorption capacities were 9.12 mg/g for Fe-BC and 14.31 mg/g for GT-Fe-BC. Characterization analyses (SEM–EDS and FTIR) confirmed successful iron incorporation and phosphate complexation with iron-containing phases. XPS analysis further revealed phosphate adsorption through Fe–O–P inner-sphere complexation and outer-sphere interactions. In comparison to Fe-BC, GT-Fe-BC worked effectively (>98% phosphate removal) over a wide pH range of 2–10, making it a robust adsorbent. The desorption studies showed sustained phosphate and iron release from both systems. Compared to Fe-BC, GT-Fe-BC showed higher release of both species, possibly due to more reactive green tea–mediated iron phases that continuously release Fe2+/Fe3+ bound to phosphate. The study suggests that both adsorbents have strong potential for phosphate recovery and subsequent reuse as slow-release fertilizers, with their application tailored to specific nutrient recovery and delivery requirements.
Abstract The glutamine synthetase (GS)/glutamate synthase (GOGAT) cycle is the main pathway for assimilating inorganic ammonium into organic molecules, being a central hub connecting carbon and nitrogen metabolisms. Recent findings suggest that the mitochondrial thioredoxin (mTRX) system can coordinate metabolic fluxes from the tricarboxylic acid (TCA) cycle toward glutamate and glutamine in a mechanism apparently independent of the redox status of GS. It remains unclear whether this mechanism involves GOGAT and glutamate dehydrogenase (GDH), other enzymes involved in glutamate metabolism. Here, we carried out bioinformatics and biochemical analyses to investigate how the absence of TRXs affects the enzyme activity of GOGAT and GDH in leaves harvested at the end of the day (ED), end of the night (EN), and after a short high-light (HL) period. We used plants lacking TRX o1 (trxo1), TRX h2 (trxh2), or both NADPH-dependent TRX reductase A and B (ntrab), alongside wild-type (WT) plants. Molecular docking revealed multiple stable interaction modes between TRX o1 and GOGAT, GDH1, and GDH2. The lowest-energy clusters indicate high-affinity binding, with distinct hotspots identified for each enzyme. These results suggest that TRX o1 may engage in several energetically favorable conformations relevant to functional or regulatory interactions. The activity of GOGAT and GDH was lower in both trxo1 and ntrab mutant lines at ED. In addition, trxo1 mutants exhibited a reduction in the potential quantum yield of PSII under HL stress, accompanied by higher activities of GOGAT and GDH compared with WT plants under HL conditions. Collectively, our results suggest that the mTRX system is important to modulate GOGAT and GDH activities, including under HL stress.
Abstract The current research assessed the influence of two key micronutrients, iron (Fe) and zinc (Zn), on muskmelon (Cucumis melo L.) microgreens, revealing comparative impacts on growth, photosynthesis, biochemical responses, and stress modulation. Differential and distinct nutrient-specific effects were observed, as iron-fortified microgreens were distinguished by improved shoot elongation, elevated levels of chlorophyll and antioxidant enzymes, including catalase (CAT), ascorbate peroxidase (APX), and guaiacol peroxidase (GPOX). While, zinc encouraged carotenoid accumulation, elevated levels of nonenzymatic antioxidants [total phenolics, total flavonoids, and total ascorbic acid (vitamin C)], greater biomass production, and improved root development. Reduced malondialdehyde (MDA) levels in both treatments indicated improved membrane stability, with ZnSO4 proving more effective in mitigating oxidative stress. A concurrent micronutrient-induced substantial enhancement in macromolecules, like proteins, carbohydrates, and antioxidants, such as phenolics, flavonoids, and ascorbate content, etc., further strengthened the idea that the addition of two key micronutrients (Fe and Zn) had improved the dietary value of muskmelon microgreens. Further, the fibrous texture and refreshing sensory profile of muskmelon microgreens supported their versatile integration into diverse dietary formats, positioning them as novel candidates for detoxification and wellness applications, leveraging their potential roles in functional food development. Incorporating these naturally sweetened, micronutrient-fed microgreens into daily meals may serve as an effective, natural, and functional food solution for sustaining energy levels, supporting nutritional diversity, and enhancing overall well-being in a health-conscious manner. The reliability and robustness of the present results were also validated with multivariate statistical tools like PCA, correlation, and radar plot analyses. The current findings underscore targeted and precise micronutrient management in optimizing plant growth and stress tolerance to address micronutrient deficiencies, increase antioxidant defense, and promote healthy consumption with longterm health and disease prevention to make a contribution toward achieving the global sustainable development goals.
Abstract Efforts to develop new herbicides are urgent due to various challenges, such as the growing prevalence of herbicide-resistant weed species. Synthetic anthranilates act as plant growth modulators and exhibit phytotoxic potential. This study investigated the phytotoxic activity of twenty-two synthetic diarylamines derived from anthranilic acid. Bioassays were conducted at concentrations of 1000, 500, and 100 µmol L–1 to evaluate the early growth of two eudicotyledonous species, lettuce (Lactuca sativa L.) and wild radish (Raphanus raphanistrum L.), as well as one monocotyledonous species, sourgrass (Digitaria insularis (L.) Fedde). In addition, physicochemical descriptors were analyzed as complementary parameters to aid the interpretation of the compounds' phytotoxic profiles. The four most phytotoxic compounds were further evaluated for their ecotoxicity in zooplankton. Within all tested compounds, nine diarylamines (1, 2, 3, 4, 5, 19, 20, 21, and 22) demonstrated significant inhibitory activity on the early growth of target plant species, particularly at the highest concentration tested (1000 µmol L–1), when compared to the solvent control. Physicochemical property analysis indicated that these compounds share structural features with commercial herbicides, which may be relevant for the discovery of new herbicidal agents. Among them, diarylamines 1–4, which feature an unsubstituted anthranilic acid moiety (A ring) connected to a mono- or di-methoxylated aromatic ring (B ring), showed the strongest inhibitory effects in weed growth bioassays. Nevertheless, zooplankton ecotoxicity assays showed no significant adverse effects from these four compounds on zooplankton richness and abundance. Therefore, diarylamines derived from anthranilic acid exhibit herbicidal potential, although further studies are required to clarify their mechanisms of action and to better assess their environmental behavior under different exposure conditions.
Abstract Slow and non-uniform germination limits pepper (Capsicum annuum) stand establishment, demanding strategies that effectively enhance seed physiological performance. This study evaluated a two-step ultrasound-based approach combining ultrasound-assisted extraction of bioactive compounds from Chlorella vulgaris with extract-mediated sonopriming of pepper seeds. The extract selected for priming showed the highest phenolic content (28.37 mg GAE L–1) and indole-3-acetic acid level (1.722 µg mL–1). Seeds were sonoprimed under different ultrasound power–time combinations, and germination, vigor, seedling growth, and redox-related responses were assessed. Ultrasound conditions markedly affected seed performance, with 60% power for 20 min achieving ∼91% germination, the highest vigor (366.73), and the greatest seedling length (4.03 cm). Enhanced performance was associated with intermediate superoxide dismutase activity (∼350.03 U mg–1 protein) and a redox-related biochemical profile compatible with improved post-germination physiological status. Multivariate analysis supported a distinct and efficient sonopriming cluster, while SEM revealed localized seed-coat modifications without structural damage. Controlled ultrasound is therefore crucial for translating microalgal bioactives into physiological benefits.
Abstract Entomopathogenic fungi of the order Hypocreales produce hydrophilic, yeast-like cells named blastospores by submerged liquid fermentation, offering promising biological alternatives for managing insect pests. However, the widespread adoption of fungal blastospores has been constrained by their limited shelf life and often inconsistent field performance. To address these technological barriers, we developed and optimized a complete bioprocess for the production, scale-up, formulation, storage, and biological evaluation of blastospores from Beauveria bassiana BRM 14527 and Cordyceps javanica BRM 14526 for controlling Bemisia tabaci and Spodoptera frugiperda, two major agricultural pests. Nutritional conditions were optimized to enhance blastospore yields, with carbon-to-nitrogen ratios of 29:1 and 36:1 yielding up to 2.33 × 109 and 2.13 × 109 blastospores mL–1, respectively. Production in laboratory shake flasks and scale-up to 7-L and 1200-L bioreactors consistently yielded >1 × 109 blastospores mL–1 within 48 h. Oil–silica formulations significantly improved the shelf life of freshly produced blastospores (up to 3.49 × 108 CFU g–1 after 90 days at 4 °C) compared with unformulated preparations. In bioassays, oil-formulated blastospores retained high virulence against S. frugiperda larvae and B. tabaci nymphs, achieving 70–93% mortality when applied at 1 × 107 blastospores mL–1. In two consecutive soybean cropping seasons, 2022/23 and 2023/24, repeated applications of blastospores in oil dispersion effectively reduced infestations of B. tabaci nymphs. These findings support the industrial mass production of highly infective blastospores along with their oil dispersion formulations as fast-acting, short-term, storage-stable mycoinsecticides for integrated pest management.
Abstract Sclerotinia minor (causing Sclerotinia blight) is a devastating pathogen in peanut production, with severe outbreaks causing up to 50% yield loss due to rapid oxalic acid (OA) accumulation. Early diagnosis is challenging because canopy-level symptoms typically emerge only after infection is well established, while early cues are subtle, stem-localized, and nonspecific; in contrast, molecular assays are time- and resource-intensive. Despite established mechanistic links between oxalate accumulation and disease progression, so far, there are no sensors developed or tested for detecting Sclerotinia blight in peanut plants. This paper reports a low-cost, lithography-free, and label-free electrochemical sensor for metabolite-targeted, presymptomatic monitoring of S. minor in peanut plants based on clear mechanistic links between oxalate accumulation and disease progression. The sensor platform comprises 3D-printed resin substrates with platinum (Pt) electrodes and a nanostructured reduced graphene oxide (rGO)−chitosan interface functionalized with an oxaloacetic acid (OAA) interfacial layer. Using ferri/ferrocyanide as a redox probe, the sensor exhibited a linear calibration to oxalate (prepared from OA) from 0.05 µM to 1 mM (R2 = 0.99), with a sensitivity of 6.37 µA/decade, limit of detection of 17.6 nM, and excellent coefficient of variation of 0.93−3.32% across standards (n = 4). In real plant trials, stem sap from S. minor-inoculated peanut plants produced significantly elevated voltammetric responses relative to healthy and Nothopassalora personata controls as early as five days post-inoculation (dpi), enabling longitudinal monitoring through 20 dpi (p < 0.001). Oxalate-equivalent mapping showed progressive increases in infected plants, reaching mM levels by 20 dpi, while the validated sensor readings agreed with those of a commercial assay during oxalate-linked S. minor detection in peanut plants. To our knowledge, this is the first demonstration of a 3D-printed, Pt-based electrochemical platform validated with peanut plants for early, metabolite-linked detection of Sclerotinia blight, providing a practical foundation for point-of-need surveillance and precision disease management in peanut production systems.
Abstract The rapid expansion of Morinda citrifolia L. (noni) cultivation in tropical regions is driven by its recognized medicinal value, yet little is known about its agronomic and physiological responses to different soil environments. In particular, the effects of soil acidity on noni seedling performance and product safety remain poorly understood. This study investigated the growth and photosynthetic responses of noni seedlings in two contrasting soils—alkaline cambisols and acidic ferralsols—and evaluated the role of biochar in soil amendment. Seedlings performed better in alkaline cambisols than in acidic ferralsols, where higher aluminum and manganese concentrations were detected in aboveground tissues. Interestingly, although leaf photosynthetic rates were higher in acidic soil, seedlings exhibited a broader range of light adaptation under alkaline conditions, indicating distinct physiological responses to soil environments. Biochar application significantly enhanced seedling biomass in acidic soil but had detrimental effects in alkaline soil. These findings reveal a strong soil-dependent physiological response of noni seedlings and demonstrate that biochar amendment must be tailored to the soil type. The study provides new agronomic insight into noni cultivation and highlights the importance of soil-specific management for the sustainable production of this medicinal crop.
Abstract Potato is a globally important food crop, but its production faces major challenges related to inefficient nitrogen fertilizer use. Excessive nitrogen application, particularly in intensive agricultural systems, compromises sustainability and increases environmental and health risks. Improving nitrogen use efficiency (NUE), defined as the capacity of plants for nitrogen uptake and assimilation, is therefore essential to optimize fertilization practices and enhance sustainable crop production. In this study, we analyzed candidate genes associated with NUE in a diploid potato diversity panel (Solanum tuberosum Group Phureja) by evaluating morphological, physiological, and biochemical variables under contrasting nitrogen levels. Association analyses were performed between these variables and genetic polymorphisms within NUE-related genes. Single nucleotide polymorphisms (SNPs) were identified in three candidate genes: AMT1.1 (ammonium transporter), 2OGDD (2-oxoglutarate-dependent dioxygenase), and PPR (pentatricopeptide repeat protein gene). These variants explained 8–20% of the phenotypic variation in traits such as relative chlorophyll content, aerial biomass, and NUE. Notably, a missense variant (Lys → Glu) in 2OGDD was associated with a 30.5% reduction in NUE under low nitrogen conditions, suggesting distinct adaptive strategies. Specific SNPs were associated with NUE-related traits, representing candidate variants for future functional validation and marker-assisted breeding.
Abstract Heavy metal contamination of agricultural soils poses risks to crop productivity and food safety. A controlled experiment evaluated the growth, physiological, biochemical, antioxidant, and yield responses of two groundnut (Arachis hypogaea L.) cultivars (GJG-9 and GJG-22) exposed to four nickel (Ni) concentrations (0, 20, 100, and 200 ppm). Measurements were recorded at 30 and 60 days after sowing and at harvest. Increasing Ni levels significantly (P ≤ 0.001) reduced plant height, biomass, photosynthetic pigments, membrane stability, and pod number, with greater reductions at higher concentrations. At 200 ppm Ni, pod number decreased by 30−45% compared with the control. Nickel stress enhanced hydrogen peroxide, malondialdehyde, proline content, and ABTS radical-scavenging activity, indicating oxidative stress and antioxidant activation. Roots accumulated more Ni than shoots, while translocation declined with increasing Ni. Cultivar GJG-22 showed greater tolerance than GJG-9, suggesting genotypic differences in Ni stress adaptation. These findings can facilitate breeding programs aimed at developing Ni-tolerant cultivars.
Abstract Climate change accelerates grape ripening, with bunch transpiration contributing to faster sugar accumulation. This study aimed to determine how bunch transpiration influences the response of grape primary and specialized metabolites to projected temperature and relative humidity (RH) changes. Fruit-bearing cuttings of cv. Tempranillo grew in greenhouses under two conditions: 24/14 °C with 55/70% RH (T) and 28/18 °C with 43/58% (T+4). At veraison, T+4 plants were split into untreated and antitranspirant-treated (AT+4) groups. T+4 reduced amino acids, anthocyanins, and hydroxycinnamic acids while increasing acylated anthocyanins as well as caftaric acid abundance. AT+4 further decreased amino acids, notably proline and aroma precursors, as well as yeast-assimilable nitrogen, and amplified the T+4-driven decline in anthocyanins. Under elevated temperature and low RH, reducing transpiration alters berry composition, highlighting berry transpiration as a critical mechanism for maintaining metabolic balance in warming climates. Factors related to the antitranspirant application may have contributed to these observed changes.
Abstract Tyrosol-derived esters were synthesized and evaluated for their inhibitory activity against Hemileia vastatrix urediniospore germination. Esterification reactions afforded mono- and diester derivatives, which were characterized by spectroscopic methods. In biological assays, all esters showed higher antifungal activity than tyrosol, whereas 1,2,3-triazole derivatives were inactive. Monoesters retaining a free phenolic hydroxyl group exhibited significantly higher activity than the corresponding diesters, highlighting the importance of this group for antifungal activity. Selected compounds displayed inhibitory effects comparable to copper oxychloride and showed low cytotoxicity in L929 fibroblast cells. In silico analysis indicated that key physicochemical parameters fell within the range of commercial fungicides. These results identify tyrosol-derived esters as promising lead structures for further investigation in the development of fungicides for coffee leaf rust control.
Abstract The development of functional nanopesticides is crucial for improving pesticide utilization efficiency and represents a major research direction in pesticide formulation. In this study, a sodium alginate-coated metal–organic framework (ZIF-8@SA) was used as a carrier to construct a tebuconazole (Teb) nano-delivery system, Teb/ZIF-8@SA, featuring foliar adhesion and pH-responsive release properties. The structure and performance of the system were systematically investigated. Results showed that Teb/ZIF-8@SA had an average particle size of approximately 394.14 nm and a pesticide loading capacity of 25.73% w/w. Its deposition on cabbage leaves was 1.29 times higher than that of a tebuconazole suspension. After simulated rainfall, the retention of active ingredient on leaves was 4.25 times greater than that of the suspension. The system exhibited distinct pH-responsive release behavior, with cumulative release rates of 61.89% at pH 7 and 89.21% at pH 5 over 84 h. Plant absorption and translocation experiments demonstrated that, seven days after foliar application, Teb content in leaves, stems, and roots of cucumber plants was 3.18, 2.59, and 1.13 times higher, respectively, compared to the suspension treatment, indicating effective uptake and translocation. In plate antifungal assays, Teb/ZIF-8@SA showed a 25.43% higher inhibition rate against Fusarium graminearum than the suspension. Moreover, acute toxicity to zebrafish was nearly tenfold lower for Teb/ZIF-8@SA than for the Teb suspension. In conclusion, this foliar-adhesive and pH-responsive nano-delivery system offers a promising strategy for sustainable agriculture development.
Abstract The development of sustainable agricultural inputs is essential to reduce the reliance on synthetic agrochemicals. Trichoderma species are widely recognized for their biocontrol potential and plant growth-promoting effects. In this study, Trichoderma asperellum and Trichoderma harzianum were cultivated under controlled conditions to produce extracellular enzymes and bioactive compounds. The resulting metabolites included compounds associated with antifungal activity, siderophore production, and phytohormone-like effects. For chitinase production, the highest activity reached 0.029 U mL–1 in medium 4 for T. asperellum, corresponding to a 70.0% increase during cultivation, whereas T. harzianum achieved 0.069 U mL–1 in medium 5, representing an 18.4% increase. Maximum protease activities were 22.04 U mL–1 in medium 3 for T. asperellum and 39.70 U mL–1 in medium 4 for T. harzianum, corresponding to increases of 58.3% and 42.1%, respectively. β–1,3-Glucanase production reached 0.088 U mL–1 in medium 2 for T. asperellum and 0.033 U mL–1 in medium 4 for T. harzianum, representing increases of 60.2% and 54.6%, respectively. The in vitro findings demonstrate a strategy for generating Trichoderma-based bioactive compounds with potential application as biocontrol agents and biofertilizers in sustainable agriculture.
Abstract Developing sustainable strategies to enhance crop yields is critical to meeting global food demands under intensifying climate stress. This study investigates the synthesis and application of folic-acid-based carbon nanoassemblies (FA-CNAs) that integrate magnesium (Mg) or manganese (Mn) as precision nanobionic tools for agricultural enhancement. The produced materials were selected for photosynthetic enhancement due to their biofortification potential and their ability to expand the usable solar spectrum by harvesting underutilized UV-A wavelengths. In greenhouse trials with Raphanus sativus, FA-CNA-Mg treatment achieved significant biostimulation, resulting in a 13% increase in foliar dry mass, a 19% boost in chlorophyll concentration, and a 22% improvement in ascorbic acid content. Conversely, while FA-CNA-Mn facilitated exceptional systemic translocation (up to a 306% increase in root Mn concentration), it displayed inhibitions in the rate of the Hill reaction by 36%. Untargeted metabolomics revealed that the superior performance of FA-CNA-Mg is underpinned by systemic metabolic reprogramming, characterized by the upregulation of vitamin B5 and an accelerated flux of essential amino acids and nitrogen-rich ureides. These results highlight the potential of vitamin–metal synergy for developing high-efficiency, sustainable alternatives to conventional fertilizers that optimize both photosynthetic integrity and harvestable yield.
Abstract Imazethapyr is a widely used persistent herbicide that causes severe phytotoxicity to rotational crops and threatens soil ecosystem health and agricultural sustainability. Although pristine biochar has been explored for pesticide-contaminated soil remediation, its low adsorption capacity and limited efficiency restrict practical application. Phosphorus (P)-doped biochar exhibits enhanced sorption ability toward organic pollutants, yet its effects and mechanisms in alleviating imazethapyr-induced soil toxicity remain largely unknown. This study systematically compared the remediation performance of P-doped corn straw biochar (PBC-500) and pristine biochar (BC-500) in imazethapyr-contaminated soil using a multimethod approach including herbicide residue analysis, wheat seedling growth assessment, soil microbial community profiling, and wheat root metabolomics. Results showed that by day 4 of the incubation, PBC-500 reduced imazethapyr concentrations in soil and pore water by 82.3%, significantly higher than the 46.1% reduction achieved by BC-500. PBC-500 effectively mitigated herbicide-induced phytotoxicity, improved wheat growth and chlorophyll content, and suppressed ROS (reactive oxygen species) accumulation. It was also associated with stabilization of the soil microbial community structure and changes of root metabolic pathways. Metabolomic analysis further showed that PBC-500 alleviated specific imazethapyr-induced metabolic perturbations at the pathway level based on candidate metabolites (screened without FDR correction), although substantial differences between IMTPBC and the control remained, indicating that the observed metabolic changes partly reflect the biochar’s own effects. However, because the experimental design lacked biochar-only controls, these microbial and metabolic effects should be interpreted as changes co-occurring with PBC-500 amendment, and their specific driver cannot be definitively isolated under the current design. Overall, P-doped biochar efficiently reduces imazethapyr bioavailability and alleviates phytotoxicity, providing a promising eco-friendly material for remediation of imazethapyr-contaminated agricultural soils, with potential for integration into rotational cropping systems to protect subsequent sensitive crops.
