The environmental fate and ecological risks of phthalate esters (PAEs) in coastal ecosystems remain poorly understood, particularly regarding their toxicological mechanisms on primary producers. This study systematically investigated the occurrence of 16 PAEs in seawater, suspended particulate matter (SPM), and sediments of Qingdao coastal waters, identifying sediments as the primary sink due to a strong "scavenging effect" in the semi-enclosed bay. The mean concentration of Σ16PAEs in seawater was 866.0 ng/L, dominated by diisobutyl phthalate (DIBP) and dibutyl phthalate (DBP). Ecological risk assessment based on the species sensitivity distribution (SSD) model revealed a critical divergence: although butyl benzyl phthalate (BBP) exhibited the highest inherent toxicity, DIBP and DBP posed the most significant individual risks driven by their high exposure levels. Crucially, a cumulative risk assessment utilizing the concentration addition (CA) model demonstrated that the mixture risk (RQmix > 1) consistently exceeded the high-risk threshold (RQmix > 1), highlighting a pervasive ecological threat. Furthermore, a mechanism-anchored hybrid toxicity model was developed to unravel the toxicity pathway within an adverse outcome pathway (AOP) framework. SHAP analysis identified the disruption of superoxide dismutase (SOD) activity as the dominant KE triggering growth inhibition. Molecular docking and dynamics simulations further explored a putative molecular initiating event (MIE): bulky PAEs (BBP/DBP) act as competitive inhibitors by stably binding to the hydrophobic pockets of antioxidant enzymes (CAT/APX), forming a persistent blockade. This study establishes a "Mechanism-Anchored Risk Assessment" framework, bridging the gap between macroscopic environmental monitoring and microscopic molecular toxicity.
Owing to its high energy density, environmental friendliness, and low cost, the high-voltage Ni-Mn-based oxides material has emerged as a highly promising cathode candidate. Nevertheless, such kind of material faces significant limitations including hydrofluoric acid (HF) corrosion, transition metal dissolution, and the Jahn-Teller effect, which substantially hinder its large-scale commercialization. This review comprehensively introduces the fundamental characteristics and limitations of LiNi0.5Mn1.5O4 (LNMO) and LiNixCoyMnzO2 (NCM), followed by state-of-the-art mitigation approaches of CEI regulation encompassing electrolyte additives, synergistic additive combinations, doping modifications, surface coating engineering, and particle design optimization. Future research could explore the synergistic combination of these modification approaches, potentially sparking novel research avenues.
The distribution of the radiological characteristics of the natural radioisotopes 40 K, 232Th, and 226Ra in the Upper Cretaceous-Lower Paleogene sedimentary rock samples collected from Wadi Queih area, Red Sea, Egypt, was measured using gamma-ray spectrometer with an NaI(Tl) detector. The sedimentary sequence under study was divided into four groups (A, B, C, D) according to the lithological variations and dominant rock type. The average activity concentrations of 226Ra, 232Th and 40 K were 309.11 ± 15.49, 336.91 ± 16.62 and 887.58 ± 44.38 Bq/kg for group (A); 240.95 ± 12.06, 396.49 ± 19.83 and 570.49 ± 31.93 Bq/kg for group (B); 260.21 ± 13.03, 333.49 ± 16.68 and 568.54 ± 28.43 Bq/kg for group (C); and 238.56 ± 11.93, 369.62 ± 18.75 and 633.32 ± 32.74 Bq/kg for group (D), respectively. For 226Ra, 232Th, and 40 K, the average activity concentrations in each of the four groups are higher than the UNSCEAR worldwide average values of 35, 30 and 400 Bq/kg, respectively. The radiological hazard parameters that were used to evaluate the radiation hazards associated with the rock samples, the calculated values of these indices exceed internationally recommended limits in several cases, indicating a non-negligible radiological risk in some rock units, particularly phosphate-rich and cherty lithologies. These findings highlight the need for radiological safety assessments in regions where such rocks are used in construction or agriculture. Given the radiological threat to residents and the need for radiation protection precautions, the collected data offer a useful future database for estimating the impact of radioactive contamination in the studied area as well as in locations where the rocks are used as building materials or in agricultural reclamations. The results also offer baseline reference values that can support future environmental monitoring, land-use planning, and radiation protection policy.
Mercury (Hg) pollution has been widely recognized for its severe ecological and health impacts on humans; however, its role in corrosion-related material degradation has received comparatively limited attention. This review examines the mechanisms and risks of mercury-induced corrosion, integrating insights from corrosion science, environmental chemistry, and industrial case studies. It also explores the effects of mercury pollution on industrial corrosion, mercury speciation, surface deposition, environmental cycling of Hg, and corrosion mechanisms, including amalgamation, liquid metal embrittlement (LME), passive film destabilization, and microgalvanic coupling. Finally, the review discusses emerging strategies to mitigate mercury-induced corrosion, including corrosion-resistant materials, protective coatings, mercury-capture technologies, and improved monitoring approaches. By linking corrosion mechanisms to environmental mercury dynamics, this work highlights the importance of integrating materials engineering, environmental risk assessment, and policy frameworks to better manage mercury-related hazards in industrial and environmental systems.
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Microplastics are pervasive environmental pollutants that pose potential risks to human health, particularly through inhalation. Despite growing concerns, limited data exist on how environmental aging, such as ultraviolet (UV) irradiation, affects the pulmonary toxicity of inhaled nano- and microplastics. This study evaluated the influence of UV-driven surface oxidation on the inflammatory potential and lung clearance kinetics of polystyrene (PS) particles. Spherical PS particles (50, 200, and 400 nm) were synthesized, selectively oxidized by UV irradiation, and thoroughly characterized for surface chemistry and intrinsic reactive oxygen species (ROS) generation. Mice exposed to these particles via pharyngeal aspiration (75 µg/mouse; n = 4 per group) exhibited significantly greater acute pulmonary inflammation from UV-oxidized particles compared to pristine particles, with smaller ones (50 nm) displaying slightly higher inflammogenicity. Although inflammation largely resolved by four weeks post-exposure (75 µg/mouse; n = 4 per group), mild neutrophilic inflammation persisted. Notably, particle-induced ROS generation and subsequent cellular oxidative stress in alveolar macrophages showed strong correlations with acute inflammatory endpoints. Additionally, the particle dispersion method significantly affected lung clearance rates: particles dispersed in distilled water (DW) containing 10% ethanol exhibited shorter clearance half-lives (3-8 days) than those dispersed in 5% mouse serum (~ 18 days) (75 µg/mouse; n = 4 per group). These results highlight the dispersion medium as an important experimental variable influencing pulmonary clearance and toxicity interpretation. These findings suggest that the surface oxidation of nano- and microplastics through environmental aging can increase associated health risks. However, within the tested size range (50-400 nm), neither surface oxidation nor particle size markedly altered the overall lung clearance pattern.
Alternative DNA structure-forming (i.e., non-B) sequences such as H-DNA-forming sequences are enriched at chromosomal translocation hotspots in human cancer genomes, underscoring their role in genomic instability. H-DNA is particularly susceptible to DNA damage by reactive oxygen species (ROS), a common byproduct from both endogenous metabolism and environmental contaminants, thereby exacerbating its mutagenic potential. Oxidative lesions within B-DNA are efficiently processed by base excision repair (BER), whereas H-DNA is processed in a mutagenic fashion by nucleotide excision repair (NER). Thus, we speculate that the repair of oxidative lesions within H-DNA will promote aberrant BER and NER processing, ultimately enhancing mutagenesis. Here, we examine the processing of oxidative damage within H-DNA by measuring the changes in mutation frequencies and spectra, as well as the association with key NER and BER proteins in human cells in the presence or absence of specific DNA repair proteins. Our results demonstrate that oxidatively damaged H-DNA serves as a substrate for both BER and NER and reveals an interplay between BER and NER proteins, which influences mutation outcomes. This novel framework establishes a link between oxidative stress, DNA repair, and H-DNA-associated mutagenesis, providing insight into how environmentally relevant DNA damage can drive sequence-specific genomic instability at cancer-associated hotspots.
Migraine is recognized as a major neurological disorder characterized by substantial global prevalence, affecting more than one billion individuals worldwide. In 2025, the FDA approved a novel fixed-dose mixture of rizatriptan (RIZ) and meloxicam (MEL) for managing acute migraine. In response, an affordable and sensitive TLC-densitometric strategy was developed for determining MEL and RIZ concurrently in their pure powders and recently approved formulation. The separation process was achieved on a 60F254 silica gel stationary phase employing a moving phase of methanol, ethyl acetate, and 25% aqueous ammonia (9:1:0.05, by volume). The medications were UV-scanned at 254.0 nm. Key chromatographic parameters influencing strategy performance were systematically investigated and optimized. Our strategy was fully validated, consistent with ICH standards, and demonstrated satisfactory linearity over concentration ranges of 2-12 μg/band for MEL and 1-6 μg/band for RIZ, along with good accuracy, robustness, precision, and selectivity, enabling reliable quantification without intrusion from common excipients. Furthermore, the environmental sustainability and overall analytical performance of our strategy were comprehensively assessed utilizing multiple appraisal tools, confirming its favorable environmental profile, balanced analytical performance, and practical applicability compared with previously documented methods. Compared with previously published LC methods, particularly UPLC, our strategy requires lower solvent consumption and reduced energy demand and generates less analytical waste owing to the simultaneous analysis of multiple samples on a single plate, while also offering greater operational simplicity. The ability to simultaneously estimate all analytes in a single TLC run cheaply renders our strategy efficient and well-suited for regular QC testing.
The discharge of synthetic dyes into aquatic systems remains a significant environmental concern due to their persistence, toxicity, and resistance to conventional treatment processes. This review critically examines recent advances (2020-2025) in glutaraldehyde-crosslinked chitosan (CS-Glu) adsorbents for dye removal from aqueous solutions. The scope covers major material families, including pristine CS-Glu hydrogels, magnetic CS-Glu composites, carbon-based hybrids, and inorganic-filler nanocomposites, as well as the adsorption of representative dye classes, such as cationic dyes (e.g., methylene blue), anionic dyes (e.g., Congo red), and reactive dyes commonly found in textile effluents. Reported adsorption capacities typically range from ∼50 to mor than 800 mg/g, depending on crosslinking density, composite structure, and operating conditions, with optimal performance generally observed within pH 4-9 and moderate ionic strength. The review discusses the crosslinking chemistry of CS-Glu systems, structure-property relationships, adsorption mechanisms (electrostatic interaction, hydrogen bonding, and π-π interactions), and the influence of physicochemical parameters on adsorption efficiency. Comparative analysis indicates that nanocomposite CS-Glu systems, particularly magnetic and carbon-based hybrids, provide improved adsorption capacity, stability, and recyclability compared with conventional chitosan adsorbents. Overall, the literature suggests that controlled crosslinking can significantly enhance chitosan stability while maintaining high adsorption performance. However, future research should prioritize testing under realistic wastewater matrices, long-term regeneration performance, and scalable synthesis strategies to facilitate practical applications.
Landfill gas (LFG) is primarily composed of CH4 and CO2, together with a wide range of trace compounds generated during the decomposition of domestic waste in landfills. During energy production from LFG, trace compounds such as sulfur-containing compounds and siloxanes cause the formation of metal oxide-based deposits. However, studies integrating gas composition with deposit chemistry, phase identification, and multi-technique validation on the same samples remain limited. This study aims to establish the linkage between LFG composition and deposit formation, focusing on the transformation of organometallic compounds into oxide phases. A multi-analytical approach including scanning electron microscopy with energy-dispersive spectroscopy, X-ray diffraction, inductively coupled plasma optical emission spectroscopy, wavelength-dispersive and energy- dispersive X-ray fluorescence was applied to characterize deposits collected from engine components. In addition to the organometallic compounds identified in standard LFG analyses at the study site, other compounds reported in the literature and detected through gas analysis were also considered. The results demonstrate that Si and S are directly associated with LFG constituents, while Ca is linked to lubricant oil additives, and metal(loid)s (Sb, Sn, As) are related to organometallic compounds present in LFG. A broad spectrum of trace elements was identified, providing comprehensive elemental coverage and highlighting potential occupational health risks associated with elements such as As, Cr, Ni, Ba, Zn, and Zr. By integrating gas composition, and deposit chemistry, this study provides new insights into deposit formation and supports the development of improved gas quality control strategies and mitigation approaches for both engine performance and health protection.
Pentachlorophenol (PCP), a highly toxic and bioaccumulative chlorinated phenol, remains a persistent threat in aquatic ecosystems due to its widespread use and environmental stability. In this study, a novel, eco-friendly, and label-free fluorescence-based sensing platform utilizing unmodified C-phycocyanin (CPC) - a naturally fluorescent, water-soluble protein - for the selective and sensitive detection of PCP in aqueous media was developed. The method exploits direct fluorescence quenching of CPC, exhibiting a clear concentration-dependent emission decrease at 644 nm with excellent linearity and reproducibility. Unlike conventional approaches relying on nanomaterials or chemically modified probes, this method employs a natural biopolymer without derivatization or signal amplification. The developed method achieved a linear detection range of 0.9-31.1 μg.mL-1, with a limit of detection (LOD) of 0.0780 μg.mL-1 and a limit of quantification (LOQ) of 0.2599 μg.mL-1. Among 28 tested analytes, only PCP caused significant quenching, highlighting the exceptional selectivity of the system. Molecular docking analysis supported these findings, revealing that PCP interacts with key residues in the β-subunit chromophore-binding pocket of CPC, consistent with the observed fluorescence quenching. Validation through spike-recovery experiments and GC-MS comparisons confirmed the method's analytical accuracy and practical applicability. This sustainable sensing approach not only broadens the scope of natural protein-based probes in analytical science but also provides an environmentally responsible platform for real-time monitoring of persistent pollutants in aquatic environments.
Two-dimensional metal-organic framework (2D-MOF) photocatalysts have gained significant attention for environmental remediation due to their improved mass transfer and photocatalytic activities. In this study, a photocatalyst based on the quasi-two-dimensional MIL-100(Fe), graphitic carbon nitride (g-C3N4), and magnetite was synthesized. All materials were thoroughly characterized via SEM, TEM, XPS, VSM, and TGA analyses. Compared to 3D-MIL-100(Fe), the quasi- two-dimensional MIL-100(Fe)-based photocatalyst exhibited significantly enhanced performance in the photodegradation of Rhodamine B under visible light. Thanks to the photocatalyst's 2D morphology and more accessible active sites, adsorption equilibrium was achieved in 60 min, compared to over 200 min for the 3D-MIL-100(Fe). Photodegradation of 99% was reached within 23 min, compared to less than 60% for the 3D-MIL-100(Fe) under the same conditions. The photodegradation mechanism proceeded via the formation of radical species, where the main active species were in the order of holes > hydroxyl radicals > superoxide radicals. Key parameters in photodegradation experiments were optimized via Box-Behnken design. The chemical and structural stability of the prepared photocatalyst was studied for up to 6 cycles, and the data showed a high performance of over 98% photodegradation. The proposed method was reproducible and yielded high amounts, showing great potential for sustainable environmental applications.
Gas-sensing technology is indispensable in fields such as environmental monitoring, industrial safety, food quality control, and medical diagnostics. Template-assisted synthesis can be employed to construct hierarchical structures in gas-sensing materials, enabling precise multiscale control over morphology, porosity, and intrinsic electronic properties, thereby paving the way for developing next-generation gas sensors with enhanced sensitivity and selectivity. Continuous innovations in the synthesis of hierarchical materials like metal oxide semiconductors (MOS) and metal-organic frameworks (MOFs) have significantly enhanced gas sensing performance in stability, response speed, sensitivity, and selectivity. However, a systematic analysis linking hierarchical structures built via different templating methods to sensing performance remains lacking. This review systematically summarizes the design principles, control mechanisms, and functional applications of three primary templating approaches. Furthermore, this work examines how tailored templating strategies can balance structural precision, synthetic complexity, and environmental impact. Finally, we offer forward-looking perspectives on future development pathways, as well as the challenges and opportunities for practical applications.
Perfluorooctanoic acid (PFOA) precursors are a class of compounds that are commonly released into the environment through aqueous film-forming foams (AFFFs) and are known to decompose into PFOA. PFOA is one of the most used per- and polyfluoroalkyl substances (PFAS), a class of highly persistent synthetic chemicals. Exposure to PFOA through environmental contamination has been linked to a variety of health concerns, and precursors from AFFFs are sources of PFOA contamination. Although PFOA precursors are often not considered, studies have demonstrated that they contribute to the overall levels of PFOA contamination, meaning that the ability to detect them is important for removing PFOA from the environment. However, the detection of PFOA precursors is limited to mass spectrometry methods, which are expensive and time-consuming. While higher-throughput methods have been developed for PFOA, no high-throughput sensing platforms have been reported for PFOA precursors. To address this problem, we developed a fluorescent sensor platform for detection and differentiation of three specific PFOA precursors, both from each other and from PFOA itself. We demonstrate that dynamic combinatorial libraries (DCLs) made up of dithiol monomers and templated with a solvatochromic fluorophore can be used to form a sensor array that achieves this detection and differentiation at low nanomolar, environmentally relevant concentrations. We can discriminate individual PFOA precursors from each other and perfluoroalkyl carboxylic acids of varying chain lengths, mixtures of varying ratios of the precursor to PFOA, and use our system in complex samples extracted from soil spiked with the precursors. To our knowledge, this is the first report of a fluorescence-based method for the detection and differentiation of PFOA precursors.
Agricultural residues offer a scalable feedstock for sustainable carbon electrodes, yet achieving high electrochemical performance in aqueous zinc-ion hybrid supercapacitors (ZHSCs) often relies on harsh activating agents and low carbon yields. Here, almond-tree pruning residues (AT) and almond shells (AS) are converted into porous carbons via hydrothermal pretreatment (HTC) followed by mild K2CO3 activation, enabling hierarchical porosity while limiting excessive burnoff. The HTC-assisted route markedly enhances N2-accessible surface area and mesopore volume, improving electrolyte accessibility and ion-transport pathways, while the presence of oxygen-containing groups contributes to favorable interfacial interactions in aqueous media. AT-derived carbons consistently outperform AS counterparts, highlighting the strong influence of precursor architecture on activation efficiency and pore connectivity. In a two-electrode aqueous ZHSC configuration (Zn metal anode; porous carbon cathode), the best performing AT-derived electrode delivered a specific capacity of 142 mAh g-1 at 0.1 A g-1 with 91% capacity retention after 10,000 cycles at 10 A g-1. Electrolyte chemistry plays a key role in durability: zinc trifluoromethanesulfonate (ZTFS) provides higher capacity retention and improved reversibility than ZnSO4, consistent with a more uniform Zn deposition and the formation of a less crystalline, fluorine-containing interphase, as evidenced by post-mortem analyses. Electrochemical impedance spectroscopy and galvanostatic intermittent titration techniques further support faster interfacial kinetics and more favorable transport in the best-performing carbon, in line with its balanced hierarchical porosity and surface chemistry. The device achieves an energy density of 87.8 Wh kg-1 at 62.3 W kg-1 and retains 37.9 Wh kg-1 at 13.6 kW kg-1, matching or surpassing many biomass-derived ZHSC cathodes prepared using more corrosive chemicals. Overall, this work demonstrates a greener, yield-efficient pathway to high-performance carbon cathodes for aqueous zinc-based hybrid energy storage.
Air pollution remains critical global challenge, with sulfur oxides (SOx), nitrogen oxides (NOx), and volatile organic compounds (VOCs) contributing to environmental degradation and adverse health outcomes. Among mitigation technologies, biochar (BC) has gained attention as sustainable adsorbent for gas-phase pollutant control due to its hierarchical porosity, tunable surface chemistry, and production from renewable biomass. This review examines mechanistic foundations and design strategies of engineered biochar for removal of SOx, NOx, and VOCs, while comparing its performance with conventional technologies that are pollutant-specific, energy-intensive, or limited under industrial conditions. Key synthesis routes including pyrolysis, hydrothermal carbonization, and co-pyrolysis are discussed alongside modification strategies such as activation, heteroatom doping, and metal functionalization, which enhance pore structure, surface reactivity, and pollutant selectivity. Reported studies indicate that engineered biochars achieve adsorption capacities up to ~ 200 mg g-1 for SO₂ and ~ 245 mg g-1 for aromatic VOCs such as toluene, while demonstrating effective NOx removal under flue-gas conditions. These performances are governed by hierarchical porosity, defect-rich carbon structures, and oxygen-containing functional groups that promote acid-base interactions, π-π stacking, and redox-mediated adsorption pathways. Computational tools increasingly support adsorbent design: Density Functional Theory provides atomistic insight, while Machine Learning enables rapid prediction across datasets. Despite progress, challenges remain, including regeneration energy demand, reduced selectivity under humid conditions, and limited industrial scalability. By integrating experimental insights with computational approaches, this review outlines a predictive framework for developing efficient and durable advanced biochar adsorbents for next-generation air pollution control.
Chemical mechanisms are one of the major sources of bias in chemical transport model simulations, making their improvement a critical step towards enhancing model performance and supporting air quality management and research. In this study, a newly developed chemical mechanism, the Community Regional Atmospheric Chemistry Multiphase Mechanism (CRACMM), integrated into the Community Multiscale Air Quality (CMAQ) modeling system, was evaluated through comparison with two traditional chemical mechanisms, Carbon Bond 6 version r3 with aero7 treatment of SOA (CB6r3_ae7) and State Air Pollution Research Center version 07tc with extended isoprene chemistry and aero7i treatment of SOA (Saprc07tic_ae7i), for China. Sensitivity simulations related to precursor reactive organic carbon (ROC) emissions were conducted to investigate the key driving factors of PM2.5 formation. The results indicate that, when using the traditional primary organic aerosol (POA) inventory, the differences among the three chemical mechanisms are within 0-0.14 for the R, 0-10 μg m-3 for the MB, and within 10 % for the NMB values. However, when the full-volatility emission inventory is applied in January, CRACMM exhibits improved performance in the Pearl River Delta (PRD) region. The MB is reduced by 3.0-7.8 μg m-3. In addition, the NMB decreases by 17 %-23 %, and the root mean square error (RMSE) is reduced by 1-6 μg m-3 compared with simulations using the traditional POA inventory across the four months. CRACMM predicts higher PM2.5 concentrations during spring, summer and autumn, mainly due to enhanced secondary organic aerosol (SOA) formation driven by increased precursor emissions. Benzene-toluene-xylene (BTX) species and semi-volatile organic compound (SVOC) emissions significantly contributed to PM2.5 formation in CRACMM. The SOA from BTX emissions accounts for nearly 50 % of the PM2.5 changes, while intermediate-volatility organic compounds (IVOC) and SVOC emissions mainly affect PM2.5 concentrations through SOA formation. These results indicate that CRACMM, when using the full-volatility inventory, can effectively compensate for the underestimation of PM2.5 mass that may occur with traditional POA treatment, particularly in regions with high photochemical activity and abundant S/IVOC precursors.
Hydrovoltaic technology can harvest electrical energy from water-solid interactions and has emerged as a promising power solution for wearable electronics due to its broad material compatibility and strong environmental adaptability. However, the selection of flexible substrates and the relatively low interfacial charge separation efficiency still restrict its widespread application. In this work, biomass-derived carbonized silk fabric was utilized as a conductive and flexible substrate, and ordered TiO2 nanowires were grown in situ on the fiber surface to construct an efficient evaporation-driven hydrovoltaic device. Subsequently, reduction-phosphorus doping, asymmetric electrode engineering, and photothermal enhancement were incorporated to regulate surface defect chemistry and establish additional internal fields, thereby promoting charge separation. Impressively, these synergistic optimizations significantly improved the electrical output, ultimately enabling the TiO2-x-P nanowire-based device to achieve a high open-circuit voltage of 868.5 mV and a short-circuit current of 18.6 μA. Additionally, devices encapsulated with plastic film can generate a sustained ∼962 mV output voltage for over 80 h. Furthermore, the device can also function as a self-powered sensor to detect ultraviolet radiation, demonstrating its multifunctionality for future wearable and sensing applications.
Classically, quorum sensing (QS) is defined as a form of bacterial communication that regulates gene expression in response to population density and other environmental conditions. While a variety of QS systems exist, N-acyl homoserine lactone-based quorum sensing (AHL-QS) is the best characterized in Gram-negative Pseudomonadota (formerly Proteobacteria), often in medically relevant taxa. However, it remains unclear what AHL-QS systems look like in underexplored environments, and how often or far the canonical model extends beyond the Pseudomonadota. Here, we investigated AHL production in environmental Bacteria from underexplored environments, including two newly described Pseudomonadota species, Brenneria uluponensis K61T, from a taro lo'i in Hawai'i, and Bradyrhizobium prioriisuperbiae BL16AT, from a lava cave on the Island of Hawai'i, and two Gram-positive Actinomycetota (formerly Actinobacteria), Pseudonocardia alni GV4, from a culture of Gloeobacter violaceus, and Rhodococcus kroppenstedtii Y88A, from a dehydrated hypersaline mat on San Salvador Island, Bahamas. Custom hidden Markov models (HMMs) were used to identify putative luxI/R homologs, followed by analyses of genomic context, luxI/R-family protein phylogeny, and LuxR domain architecture. AHL production was assessed using liquid chromatography-multiple reaction monitoring-mass spectrometry (LC-MRM-MS), and targeted gene disruption was performed in R. kroppenstedtii Y88A. Putative luxI/R homologs were identified in all strains. In R. kroppenstedtii Y88A, disruption of the sole luxI homolog resulted in loss of all detectable AHLs, indicating that this gene (designated rhdI) is required for AHL production under the tested conditions. Across Actinomycetota genomes, luxI genes occurred as solitary elements rather than canonical luxI/R pairs and were associated with genes linked to metabolism and redox processes. Phylogenetic analyses revealed that Actinomycetota luxI/R-family proteins diverge from canonical systems, with LuxR-family proteins lacking canonical autoinducer-binding domains and instead comprising only helix-turn-helix regulatory architectures. Together, these findings expand the known diversity of AHL-QS systems into underexplored microbial lineages and environments and suggest broader ecological roles for AHL signaling. The canonical luxI/R model derived largely from Pseudomonadota may represent only one of several evolutionary architectures for AHL signaling, raising the possibility that AHL production in Actinomycetota operates through regulatory frameworks distinct from classical AHL-QS systems.
The domain of unknown function 630 (DUF630) protein family play a significant role in plant development and abiotic stress responses. However, their exact roles in soybean have not been thoroughly investigated. This study provides a comprehensive analysis of the GmDUF630 gene family, which was categorized into four distinct phylogenetic groups. Gene expression profiling revealed distinct patterns, with a strong stress response exhibited by a GmDUF630 gene cluster. Notably, GmDUF630-31 showed a 9-fold increase under drought stress. Gene promoter analysis revealed cis-regulatory elements associated with developmental processes and abiotic stress response. Tissue-specific expression was also observed. Furthermore, GmDUF630-3 was expressed at a 7-fold higher level expression in leaves, while GmDUF630-13 and GmDUF630-10 were expressed at a 15-fold and 20-fold higher level in roots and stems, respectively. These results strongly indicate that the GmDUF630 gene family is crucial for soybean adaptation to environmental stresses, making it a valuable source of candidate genes for developing stress-resilient soybean varieties.