Taurine (TAU) has recently been found to have an impactful role in regulating plant responses under abiotic stresses. This study presented the comparative effects of TAU seed priming and foliar spray application on chickpea plants exposed to hexavalent chromium. Taurine priming and foliar applications (1.6 and 2.4 mM) notably modulated morpho-physiological and biochemical responses of plants under Cr(VI) stress. Plants subjected to 25 mg kg-1 soil Cr in the form of potassium dichromate (K2Cr2O7) displayed a significant reduction in growth, chlorophyll, and uptake of essential nutrients (N, K, P, and Ca). Cr(VI) toxicity also resulted in a notable increase in osmolyte accumulation, lipid peroxidation, relative membrane permeability, ROS generation, antioxidant enzyme activities, antioxidant compounds, endogenous Cr levels, and aerial Cr translocation. Taurine abridged lipoxygenase activity to diminish lipid peroxidation owing to the overproduction of ROS initiated by a higher Cr content. The acquisition and assimilation of essential nutrients were augmented by the TAU-related decrease in leaf and root Cr levels. Consequently, TAU enhanced growth by mitigating oxidative damage, reducing Cr content in the aerial parts, and reinforcing the activities of antioxidant enzymes. Compared to foliar spray, TAU seed priming has demonstrated superior efficacy in mitigating Cr phytotoxicity in plants.
Tidal wetlands provide critical ecosystem functions for coastal communities including flood protection, water filtration, carbon sequestration and aquatic nursery habitat. However, New York City's salt marshes, including our study site at Pelham Bay Park's Turtle Cove, are rapidly disappearing due to accelerating relative sea-level (RSL) rise and coastal development. Field research, mapping and satellite imagery reveal significant loss of this similar to 10 hectare (ha) wetland, as perturbations from human activity prevent marsh landward migration, impede tidal flows and threaten marsh survival. We extracted three sediment cores and conducted 20 m transects across a gradient of disturbed marsh areas. We present the analyses of land-use change, X-ray fluorescence (XRF), loss on ignition (LOI), stable carbon isotopes (delta 13C), foraminifera, and accelerator mass spectrometry (AMS) radiocarbon dating of terrestrial macrofossils to examine the past and to inform future conditions for this rapidly eroding wetland. Moreover, we reconstruct sea level over a millennium to analyze changes in marsh plant communities in response to RSL rise and coastal development. We found that between 1974 and 2018 CE, similar to 65% of marsh disappeared at a rate of 1.5% yr-1 or 800 m2 yr-1. The marsh loss coincided with increasing RSL rates of 3.5 mm yr-1 from 1958-1975 CE to 6.7 mm yr-1 from 1999-2024 CE. Meanwhile, developed areas expanded 568 m2 yr-1 from 1985-2023 CE, replacing wetland areas and disrupting hydrologic processes with hardened shorelines. Marsh loss resulted in the release of soil organic carbon stored over many centuries and a concerning amount of lead (Pb) into Long Island Sound, presenting risks to public health and wildlife. Culvert assessments demonstrated that tidal restriction by built structures contributed to rising tide levels comparable to RSL rise over the past century, which likely exacerbated marsh erosion. Lastly, tidal prism reductions caused enough accumulation of heavy metals to significantly alter peat chemical composition for a century. This study improves our understanding of compounded stressors that prevent the capacity of salt marshes to with stand anthropogenic impacts. Ultimately, our findings inform an adaptive management of these threatened ecosystems in their struggle to keep pace with climate change and urbanization.
As the increasing demand for deep mineral resource extraction and the construction of deep vertical shafts by the artificial ground freezing method, the stability and safety of shaft that traverse thick alluvial depend significantly on their interaction with the surrounding deep frozen soil medium. Such interaction is directly conditioned by the mechanical properties of the deep frozen soil. To precisely capture these in-situ mechanical properties, the mechanical parameters tests using remodeled frozen specimens cannot ignore the disparities in consolidation history, stress environment and formation conditions between the deep and shallow soils. This study performs a series of long-term high-pressure K0 consolidation (where K0 represents the static earth pressure coefficient, describing the ratio of horizontal to vertical stress under zero lateral strain conditions), freezing under sustained load and unloading triaxial shear tests utilizing remodeled deep clay. This study presents the response of unloading strength and damage properties under varying consolidation stresses, durations, and freezing temperatures. The unloading strength increases sharply and then stabilizes with consolidation time. The unloading strength shows an approximate linear positive correlation with the consolidation stress, while a negative correlation with the freezing temperature. The strengthening rate of the unloading strength due to freezing temperature tends to decrease with increasing consolidation time. Additionally, an improved damage constitutive model was proposed and validated by incorporating the initial K0 stress state and a Weibull-based assumption for damage elements. Based on the back propagation (BP) neural network, a prediction method for the stress-strain curve was offered according to the consolidation stress level, initial stress state, and temperature. These results can provide references for improving the mechanical testing methods of deep frozen clay and revealing differences in mechanical properties between deep and shallow soils.
The aerosol scattering phase function (ASPF), a crucial element of aerosol optical properties, is pivotal for radiative forcing calculations and aerosol remote sensing detection. Current detection methods for the ASPF include multi-sensor detection, single-sensor rotational detection and imaging detection. However, these methods face challenges in achieving high-resolution full-angle measurement, particularly for small forward (i.e., less than 10 degrees) or backward (i.e., more than 170 degrees) scattering angles in open path. In this work, a full-angle ASPF detection system based on the multi-field-of-view Scheimpflug lidar technique has been proposed and demonstrated. A 450 nm continuous-wave semiconductor laser was utilized as the light source and four CMOS image sensors were employed as detectors. To detect the full-angle ASPF, four receiving units capture angular scattering signals across different angle ranges, namely 0 degrees-20 degrees, 10 degrees-96 degrees, 84 degrees-170 degrees, 160 degrees-180 degrees, respectively. The influence of the relative illumination and angular response of the used image sensors have been corrected, and a signal stitching algorithm was developed to obtain a complete 0-180 degrees angular scattering signal. Atmospheric measurements have been conducted by employing the full-angle ASPF detection system in open path. The experimental results of the ASPF have been compared with the AERONET data from the Socheongcho station and simulated ASPF based on the typical aerosol models in mainland China, showing excellent agreement. The promising results demonstrated in this work have shown a great potential for detecting the full-angle ASPF in open path.
Bioindication is a key tool for monitoring habitat quality and ecosystem dynamics under increasing anthropogenic pressure. Among model organisms, ground beetles (Coleoptera: Carabidae) play a particularly important role, and one of the widely applied functional indicators describing their assemblage structure is the Mean Individual Biomass (MIB). Introduced in the 1980s, this index reflects the average body mass of Carabidae and allows assessment of successional stages. Its computational simplicity and intuitive interpretation have led to its application in forests, agricultural landscapes, post-industrial areas, and glacier forelands. This paper synthesizes the development and applications of the MIB, highlighting both its advantages and methodological limitations (including variability of length-mass models, seasonal activity patterns, and dependence on sampling methods). Particular attention is given to the potential of the MIB in the context of global environmental change, including its role as an indicator of ecosystem responses to climate change and processes related to soil carbon sequestration. Based on a literature review, future research directions are identified, encompassing methodological standardization, integration of MIB with other ecological and molecular indicators, and expansion of analyses to regions beyond Europe. By linking classical bioindication with ecosystem functioning studies, the MIB may serve as a universal tool for environmental monitoring and the assessment of ecosystem services under accelerated global change.
Simple Summary The enzymic latch and iron gate theories represent two prevailing and contrasting mechanisms governing ecosystem carbon stability: the former via a phenolics accumulation mediated biochemical cascade that suppresses hydrolytic enzyme activity, and the latter via an abiotic pathway where ferrous iron oxidation suppresses phenol oxidase activity and promotes iron-bound soil organic carbon formation. Therefore, deciphering the stabilization mechanisms for the vast carbon stocks in permafrost peatlands represents a central challenge for climate change projections. In this study, we assessed the spatial distribution and interrelationships of peatland soil extracellular enzyme activities, iron phases, and iron-bound soil organic carbon across three permafrost zones in the Great Hing'an Mountains. Contrary to the enzymic latch mechanism, our data revealed that hydrolytic enzyme activities (beta-glucosidase, cellobiohydrolase, and beta-N-acetylglucosaminidase) were neither negatively correlated with phenolics nor positively correlated with phenol oxidase activity. Instead, iron emerged as the central regulator, with a positive correlation between ferrous iron and phenol oxidase activity and with ferric iron stabilizing soil organic carbon through co-precipitation. Our results highlighted that permafrost degradation could poses a threat to the dominant iron gate carbon sequestration mechanism in peatlands, potentially triggering a positive climate feedback.Abstract Distinct paradigms, such as the enzymic latch and iron gate theories, have been proposed to elucidate SOC loss or accumulation, but their relative significance and whether they are mutually exclusive in permafrost peatlands remain unclear. To address this, we evaluated their relative importance and identified the dominant factors controlling SOC stability. Therefore, we employed a space-for-time substitution approach across a permafrost gradient (continuous, discontinuous, and isolated) by systematically quantifying extracellular enzyme activities, iron (Fe) phases, and iron-bound soil organic carbon (Fe-SOC) at various depths (0-10, 10-30, and 30-50 cm) in peatlands. Our results did not support the enzymic latch theory, with hydrolytic enzyme activities (beta-glucosidase (BG), cellobiohydrolase (CBH), and beta-N-acetylglucosaminidase (NAG)) showing positive correlations with phenolics but negative correlations with phenol oxidase (PHO) activity. However, ferrous iron (Fe(II)) was significantly positively correlated with PHO activity, and ferric iron (Fe(III)) stabilized SOC through co-precipitation with it to form Fe-SOC, supporting the iron gate theory. Moreover, Fe-SOC decreased from the continuous to the isolated permafrost zone, and with soil depth from 0-10 cm to 30-50 cm. Partial least squares path modeling (PLS-PM) analysis indicated that Fe(III) directly and indirectly (via Fe-SOC and phenolics) affected SOC. Our study demonstrated the primacy of the iron gate mechanism in controlling carbon stability in the Great Hing'an Mountains permafrost peatlands, providing new insights for projecting carbon-climate feedback.
Salinity stress is one of the most detrimental abiotic factors affecting plant development, harming vast swaths of agricultural land worldwide. Silicon is one element that is obviously crucial for the production and health of plants. With the advent of nanotechnology in agricultural sciences, the application of silicon oxide nanoparticles (SiO-NPs) presents a viable strategy to enhance sustainable crop production. The aim of this study was to assess the beneficial effects of SiO-NPs on the morpho-physio-biochemical parameters of rice (Oryza sativa L., variety: DRR Dhan 73) under both normal and saline conditions. To create salt stress during transplanting, 50 mM NaCl was injected through the soil. 200 mM SiO-NPs were sprayed on the leaves 25 days after sowing (DAS). It was evident that salt stress significantly hindered rice growth because of the reductions in shot length (41 %), root length (38 %), shot fresh mass (40 %), root fresh mass (47 %), shoot dry mass (48 %), and root dry mass (39 %), when compared to controls. Together with this growth inhibition, elevated oxidative stress markers including a 78 % increase in malondialdehyde (MDA) and a 67 % increase in hydrogen peroxide (H2O2) indicating enhanced lipid peroxidation were noted. Increasing the chlorophyll content (14 %), photosynthetic rate (11 %), protein levels, total free amino acids (TFAA; 13 %), and total soluble sugars (TSS; 11 %), all help to boost nitrogen (N; 16 %), phosphorous (P; 14 %), potassium (K; 12 %), and vital nutrients. The adverse effects of salt stress were significantly reduced by exogenous application of SiO-NPs. Additionally; SiO-NPs dramatically raised the activity of important antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POX), and catalase (CAT), improving the plant's ability to scavenge reactive oxygen species (ROS) and thereby lowering oxidative damage brought on by salt. This study highlights SiO-NPs' potential to develop sustainable farming practices and provides significant new insights into how they enhance plant resilience to salinity, particularly in salt-affected regions worldwide.
A group of earthquakes typically consists of a mainshock followed by multiple aftershocks. Exploration of the dynamic behaviors of soil subjected to sequential earthquake loading is crucial. In this paper, a series of cyclic simple shear tests were performed on the undisturbed soft clay under different cyclic stress amplitudes and reconsolidation degrees. The equivalent seismic shear stress was calculated based on the seismic intensity and soil buried depth. Furthermore, reconsolidation was conducted at the loading interval to investigate the influence of seismic history. An empirical model for predicting the variation of the accumulative dissipated energy with the number of cycles was established. The energy dissipation principle was employed to investigate the evolution of cyclic shear strain and equivalent pore pressure. The findings suggested that as the cyclic stress amplitude increased, incremental damage caused by the aftershock loading to the soil skeleton structure became more severe. This was manifested as the progressive increase in deformation and the rapid accumulation of dissipated energy. Concurrently, the reconsolidation process reduced the extent of the energy dissipation by inhibiting misalignment and slippage among soil particles, thereby enhancing the resistance of the soft clay to subsequent dynamic loading.
Intervertebral disc degeneration (IVDD) is a globally prevalent disease, yet achieving dual repair of tissue and function presents significant challenges. Considering reactive oxygen species (ROS) is a primary cause of IVDD, and given the decrease of nucleus pulposus cells (NPCs) and extensive degradation of extracellular matrix (ECM) during IVDD development, the present study, inspired by the seeds-and-soil strategy, has developed NPCsloaded TBA@Gel&Chs hydrogel microspheres. These microspheres serve as exogenous supplements of NPCs and ECM analogs, replenishing seeds and soil for nucleus pulposus repair, and incorporating polyphenol antioxidant components to interrupt the oxidative stress-IVDD cycle, thereby constructing a microsphere system where NPCs and ECM support each other. Experiments proved that TBA@Gel&Chs exhibited significant extra-cellular ROS-scavenging antioxidant capabilities while effectively upregulating intracellular antioxidant proteins expression (Sirt3 and Sod2). This dual-action antioxidant capability effectively protects the vitality and physiological functions of NPCs. The therapeutic effects of microspheres on IVDD were also confirmed in rat models, which was found significantly restore histological structure and mechanical properties of degenerated discs. Additionally, RNA-seq results have provided evidences of antioxidant mechanism by which TBA@Gel&Chs protected NPCs from oxidative stress. Therefore, the NPCs-loaded TBA@Gel&Chs microspheres developed in this study have achieved excellent therapeutic effects, offering a paradigm using antioxidant biomaterials combined with cellular therapy for IVDD treatment.
Thallium sulphate (TLM) is a highly hazardous metal known to induce severe renal damage. Syringetin (SGN) is a naturally derived polyphenolic compound that demonstrates excellent medicinal properties. This research trial was conducted to determine the nephroprotective ability of SGN to inhibit TLM induced renal toxicity in rats by assessing different parameters including oxidative stress, apoptotic and inflammatory markers as well as histomorphological parameters. Thirty-two Sprague Dawley rats were apportioned into the control, TLM (6.4 mgkg- 1), TLM (6.4 mgkg- 1) + SGN (10 mgkg- 1) and SGN (10 mgkg- 1) alone administered group. Our findings revealed that TLM exposure promoted renal inflammation which was evident by increased mRNA expression of myeloid differentiation primary response 88 (MYD88), toll-like receptor 4 (TLR4), interleukin-1 beta (IL-1 beta), high mobility group box1 (HMGB1), tumor necrosis factor- alpha (TNF-alpha), receptor for advanced glycation end products (RAGE), cyclooxygenase-2 (COX-2), interleukin-6 (IL-6), and nuclear factor- kappa B (NF-kappa B). The concentrations of reactive oxygen species (ROS) and malondialdehyde (MDA) were exacerbated while the enzymatic action of heme oxygenase-1 (HO-1), superoxide dismutase (SOD), glutathione reductase (GSR), catalase (CAT), & tissue contents of glutathione (GSH) were reduced after TLM intoxication. Serum concentrations of N-Acetylglucosamine (NAG), blood urea nitrogen (BUN), Kidney Injury Molecule-1 (KIM-1), Neutrophil Gelatinase-Associated Lipocalin (NGAL), creatinine, uric acid were observed elevated while a notable reduction was noted in the concentration of creatinine clearance following the dose administration of TLM. The levels of Bcl-2-associated X protein (Bax), cysteine-aspartic acid protease-3 (Caspase-3) & cysteine-aspartic acid protease-9 (Caspase-9) were exacerbated while the concentration of B-cell lymphoma-2 (Bcl-2) was notably suppressed following regimen of TLM. Renal tissues were distorted after TLM administration. In contrast, SGN supplementation notably restored oxidative profile, reduced pro-inflammatory and apoptotic markers as well as improved renal histology.