Search Results (192)

Microgreens, having short growth cycles and efficient nutrient uptake, are ideal candidates for biofortification. This study investigated the effects of selenium (Se) and zinc (Zn) on photosynthetic performance in four hydroponically grown Brassica microgreens (broccoli, pak choi, kohlrabi, and kale), using direct and modulated chlorophyll a fluorescence and chlorophyll-to-carotenoid ratios (Chl/Car). The plants were treated with Na₂SeO₄ at 0 (control), 2, 5, and 10 mg/L or ZnSO₄ × 7H₂O at 0 (control), 5, 10, and 20 mg/L. The results showed species-specific responses with Se or Zn uptake. Selenium enhanced photosynthetic efficiency in a dose-dependent manner for most species (8–26% on average compared to controls). It increased the plant performance index (PI_tot), particularly in pak choi (+62%), by improving both primary photochemistry and inter-photosystem energy transfer. Kale and kohlrabi exhibited high PSII-PSI connectivity for efficient energy distribution, with increased cyclic electron flow around PSI and reduced Chl/Car up to 8.5%, while broccoli was the least responsive. Zinc induced variable responses, reducing PI_tot at lower doses (19–23% average decline), with partial recovery at 20 mg/L (9% average reduction). Broccoli exhibited higher susceptibility, with inhibited Q_A re-oxidation, low electron turnover due to donor-side restrictions, and increased pigment ratio (+3.6%). Kohlrabi and pak choi tolerated moderate Zn levels by redirecting electron flow, but higher Zn levels impaired PSII and PSI function. Kale showed the highest tolerance, maintaining stable photochemical parameters and total electron flow, with increased pigment ratio (+4.5%) indicating better acclimation. These results highlight the beneficial stimulant role of Se and the dual essential/toxic nature of Zn, thus emphasizing genotype and dose-specific optimizations for effective biofortification. Full article

The extracellular matrix (ECM) is a collagen-based scaffold that provides structural support and regulates nutrient transport and cell signaling. ECM homeostasis depends on a dynamic balance between synthesis and degradation, the latter being primarily mediated by matrix metalloproteinases (MMPs). These enzymes are secreted as pro-forms and require activation to degrade ECM components. Their activity is modulated by tissue inhibitors of metalloproteinases (TIMPs). Aging disrupts this balance, leading to the accumulation of oxidized, cross-linked, and denatured matrix proteins, thereby impairing ECM function. Bruch’s membrane, a penta-laminated ECM structure in the eye, plays a critical role in supporting photoreceptor and retinal pigment epithelium (RPE) health. Its age-related thickening and decreased permeability are associated with impaired nutrient delivery and waste removal, contributing to the pathogenesis of age-related macular degeneration (AMD). In AMD, MMP dysfunction is characterized by the reduced activation and sequestration of MMPs, which further limits matrix turnover. This narrative review explores the structural and functional changes in Bruch’s membrane with aging, the role of MMPs in ECM degradation, and the relevance of these processes to AMD pathophysiology, highlighting emerging regulatory mechanisms and potential therapeutic targets. Full article

Introduction: Celiac disease (CD) impairs bone development in children through inflammation and nutrient malabsorption. Osteoprotegerin (OPG), a decoy receptor for RANKL, plays a role in bone remodeling and is increasingly recognized as a potential biomarker of bone metabolism and inflammation. However, its clinical significance in pediatric CD remains unclear. Aim: To evaluate the relationship between OPG levels, growth parameters, and delayed bone age in children with CD, and to assess OPG’s potential as a biomarker of bone health and disease activity. Methods: This three-year case–control study included 146 children: 25 with newly diagnosed CD (Group A), 54 with established CD on a gluten-free diet (Group B), and 67 healthy controls (Group C). Participants underwent clinical, anthropometric, and laboratory assessments at baseline and after 6 months (Groups A and B). OPG and osteocalcin were measured, and bone age was assessed radiologically. Statistical analyses included ANOVA, Spearman’s correlations, and binomial logistic regression. Results: OPG levels were highest in newly diagnosed children (Group A), showing a non-significant decrease after gluten-free diet initiation. OPG correlated negatively with age and height in CD patients and controls, and positively with hemoglobin and iron in Group B. Logistic regression revealed no significant predictive value of OPG for delayed bone age, although a trend was observed in Group B (p = 0.091). Children in long-term remission exhibited bone maturation patterns similar to healthy peers. Conclusions: OPG levels reflect disease activity and growth delay in pediatric CD but lack predictive power for delayed bone age. While OPG may serve as a secondary marker of bone turnover and inflammatory status, it is not suitable as a standalone biomarker for skeletal maturation. These findings highlight the need for integrative biomarker panels to guide bone health monitoring in children with CD. Full article

This study compiles and updates data to construct the phosphorus budget of the Archipelago Sea (northern Baltic Sea, Europe), with a particular focus on estimating phosphorus pools associated with fish populations. Biomass data and species-specific phosphorus content were utilized, and a bioenergetic modeling approach was applied to Baltic herring (Clupea harengus membras) and European perch (Perca fluviatilis) to estimate species-specific food consumption and nutrient excretion. Between 2001 and 2024, average total phosphorus concentrations were 28% higher than during the baseline period of 1983–1989. From 1998 to 2023, the annual average fish catch in the Archipelago Sea was 15,516.5 tons (16.3 kg/ha), with 73.1% consisting of commercially harvested herring. Other abundant catch species included, for example, pikeperch (Sander lucioperca), northern pike (Esox lucius), and European smelt (Osmerus eperlanus). On average, the annual catch contained 83.4 tons of phosphorus. Fishing may have annually removed an amount of phosphorus equivalent to approximately 0.6% of the total phosphorus pool in the water column and surface sediment, or 1.4% of the estimated total phosphorus load to the Archipelago Sea. The contribution of fish to phosphorus turnover is minor, as nutrient recycling is dominated by plankton. Planktivorous fish and their prey recycle nutrients already present in the water column and are therefore not the primary drivers of eutrophication. Full article

Leaf litter traits among tree species exert a direct influence on spatiotemporal nutrient turnover and an indirect influence by shifting the decomposition dynamics of leaf litter mixtures including other sympatric species. Cycas micronesica and Serianthes nelsonii are two Mariana Island tree species that are endangered, and developing a greater understanding of the influence of these trees on biogeochemistry may improve information-based conservation decisions. The objectives of this study were to quantify the influence of mixing the leaf litter of these species with 12 sympatric forest plants to determine the additive and nonadditive influences on decomposition. The C. micronesica litter was collectively antagonistic when litter mixtures were incubated in a mesocosm study and a field litterbag study, and the response was similar among the included species. The S. nelsonii litter was collectively synergistic among the same mixed species, and the response was dissimilar among the included species. The contributions of these two threatened tree species to spatiotemporal diversity in biogeochemistry are dissimilar and considerable. These findings indicate that species recovery efforts for these two species are of paramount importance for maintaining Mariana Island ecological integrity and native biodiversity by sustaining their contributions to ecosystem services. Full article

Malignant cells exhibit elevated rates of protein synthesis and secretion to facilitate tumor growth, proliferation, and tumorigenesis. Upon malignant transformation, the endoplasmic reticulum (ER) experiences stress due to the accumulation of unfolded or misfolded proteins in the ER lumen, lack of nutrient availability and overall hostile tumor microenvironment conditions. The demand for regulated protein turnover and proteostasis reinstatement results in the activation of the unfolded protein response (UPR) pathway for cellular adaptation and survival. The UPR machinery utilizes the BiP chaperone and three ER-bound sensors, PERK, IRE1, and ATF6, to substantiate signal transduction and orchestrate gene expression associated with protein folding, degradation and recycling, inflammation, autophagy, and programmed cell death. The pleiotropic function of UPR emerges as a central mediator for tumor progression, especially in multiple myeloma and glioblastoma pathologies. Numerous studies have recently pointed out that communication of the extracellular matrix (ECM) with surrounding tumor cells dictates in part UPR activity and vice versa. In the context of this dynamic interplay, ER stress and UPR mechanisms have been proposed as potential targets to elicit novel and effective therapeutic approaches in clinical trials. Full article

This study explores the spatiotemporal dynamics of SOC and microbial-mediated mechanisms in the Yellow River Delta wetlands. Using redundancy analysis and microbial community profiling, we show that vegetation drives distinct SOC storage patterns: Phragmites australis ecosystems exhibit the highest SOC sequestration, followed by Suaeda salsa and Tamarix chinensis habitats, where salt-tolerant taxa like Desulfobacterota and Halobacteriaota promote short-term carbon storage via anaerobic metabolism. The microbial community structure is shaped by both vegetation-induced microhabitats and environmental gradients: SOC and total nitrogen dominate community assembly, while electrical conductivity, pH, and sulfur/nitrogen nutrients regulate spatiotemporal differentiation. Seasonal turnover drives the reorganization of microbial community structures, shaping the dynamic equilibrium of carbon pools. Seasonal DOC dynamics, linked to tidal fluctuations and exogenous carbon inputs, highlight hydrology’s role in modulating active carbon pools. These findings reveal tight linkages among vegetation, microbial functional guilds, and soil biogeochemistry, critical for wetland carbon sequestration. Full article

The term autophagy identifies several mechanisms that mediate the degradation of intracellular and extracellular components via the lysosomal pathway. Three main forms of autophagy exist, namely macroautophagy, chaperone-mediated autophagy, and endosomal microautophagy, which have distinct mechanisms but share lysosomes as the final destination of their cargo. A basal autophagic flux is crucial for the maintenance of cellular homeostasis, being involved in the physiological turnover of proteins and organelles. Several stressors, including nutrient shortage and genotoxic and oxidative stress, increase the autophagic rate, which prevents the accumulation of damaged and potentially harmful cell components, thus preserving cell viability. In this context, several studies have highlighted the role of MAPKs, serine–threonine kinases activated by several stimuli, in linking oxidative stress and autophagy. Indeed, several oxidative stressors activate autophagy by converging on MAPKs, directly or indirectly. In this regard, the different transcription factors that bridge MAPKs and autophagic activation are here described. In this review, we summarize the current knowledge regarding the regulation of autophagy by MAPK, including the atypical ones, with a particular focus on the regulation of autophagy by oxidative stress. Full article

Wetlands and meadows are two terrestrial ecosystems that are strikingly distinct in terms of hydrological conditions and biogeochemical characteristics. Wetlands generally feature saturated soils, high accumulation of organic matter, and hypoxic environments. They support unique microbial communities and play crucial roles as carbon sinks and nutrient retainers. In contrast, meadows are characterized by lower water supply, enhanced aeration, and accelerated turnover of organic matter. The transition from wetlands to meadows under global climate change and human activities has triggered severe ecological consequences in the Sanjiangyuan region, yet the mechanisms driving microbial network stability remain unclear. This study integrates microbial sequencing, soil physicochemical analyses, and structural equation modeling (SEM) to reveal systematic changes in microbial communities during wetland degradation. Key findings indicate: (1) critical soil parameter shifts (moisture: 48.5%→19.3%; SOM: −43.6%; salinity: +170%); (2) functional microbial restructuring with drought-tolerant Actinobacteria (+62.8%) and Ascomycota (+48.3%) replacing wetland specialists (Nitrospirota: −43.2%, Basidiomycota: −28.6%); (3) fundamental network reorganization from sparse wetland connections to hypercomplex meadow networks (bacterial nodes +344%, fungal edges +139.2%); (4) SEM identifies moisture (λ = 0.82), organic matter (λ = 0.68), and salinity (λ = −0.53) as primary drivers. Particularly, the collapse of methane-oxidizing archaea (−100%) and emergence of pathogenic fungi (+28.6%) highlight functional thresholds in degradation processes. These findings provide microbial regulation targets for wetland restoration, emphasizing hydrologic management and organic carbon conservation as priority interventions. Future research should assess whether similar microbial and network transitions occur in degraded wetlands across other alpine and temperate regions, to validate the broader applicability of these ecological thresholds. Restoration efforts should prioritize re-saturating soils, reducing salinity, and enhancing organic matter retention to stabilize microbial networks and restore essential ecosystem functions. Full article

Benthic microbial communities are a vital component of coastal subtidal zones, playing an essential role in nutrient cycling and energy flow, and are fundamental to maintaining the stability and functioning of marine ecosystems. However, the response of benthic prokaryotic and eukaryotic microbial communities to environmental changes remains poorly understood. Herein, we conducted a nearly semimonthly annual sampling survey to investigate the temporal patterns and underlying mechanisms of benthic prokaryotic and eukaryotic microbial communities in the subtidal sediments of Sanshan Island, situated in the eastern Laizhou Bay of the Bohai Sea, China. The results showed that the temporal variations in benthic microbial communities followed a distinct seasonal pattern, with turnover playing a more dominant role in community succession. Nonetheless, contrasting temporal variations were observed in the alpha diversity of benthic prokaryotic and eukaryotic microbial communities, as well as in the dominant taxa across different microbial communities. Water temperature, dissolved oxygen, electrical conductivity, salinity, total nitrogen (TN), NH₄⁺, and PO₄³⁻ were identified as the predominant environmental drivers. The assembly of benthic microbial communities was driven by different ecological processes, in which stochastic processes mainly shaped the benthic prokaryotic communities, while deterministic processes dominated the assembly of benthic eukaryotic microbial communities. Interactions within benthic microbial communities were primarily characterized by mutualistic or cooperative relationships, but the ability of prokaryotic and eukaryotic microbial communities to maintain stability under environmental disturbances showed notable differences. These results shed light on the temporal dynamics and potential driving mechanisms of benthic prokaryotic and eukaryotic microbial communities under environmental disturbances, highlighting the distinct roles of prokaryotic and eukaryotic communities in coastal subtidal zones and providing valuable insights for the management and conservation of coastal subtidal marine ecosystems. Full article

Elephants exhibit remarkable cognitive and social abilities, which are integral to their navigation, resource acquisition, and responses to environmental challenges such as climate change and human–wildlife conflict. Their capacity to acquire, recall, and utilise spatial information enables them to traverse large, fragmented landscapes, locate essential resources, and mitigate risks. While older elephants, particularly matriarchs, are often regarded as repositories of ecological knowledge, the mechanisms by which younger individuals acquire this information remain uncertain. Existing research suggests that elephants follow established movement patterns, yet direct evidence of intergenerational knowledge transfer is limited. This review synthesises current literature on elephant navigation and decision-making, exploring how their behavioural strategies contribute to resilience amid increasing anthropogenic pressures. Empirical studies indicate that elephants integrate environmental and social cues when selecting routes, accessing water, and avoiding human-dominated areas. However, the extent to which these behaviours arise from individual memory, social learning, or passive exposure to experienced individuals requires further investigation. Additionally, elephants function as ecosystem engineers, shaping landscapes, maintaining biodiversity, and contributing to climate resilience. Recent research highlights that elephants’ ecological functions can indeed contribute to climate resilience, though the mechanisms are complex and context-dependent. In tropical forests, forest elephants (Loxodonta cyclotis) disproportionately disperse large-seeded, high-carbon-density tree species, which contribute significantly to above-ground carbon storage. Forest elephants can improve tropical forest carbon storage by 7%, as these elephants enhance the relative abundance of slow-growing, high-biomass trees through selective browsing and seed dispersal. In savannah ecosystems, elephants facilitate the turnover of woody vegetation and maintain grassland structure, which can increase albedo and promote carbon sequestration in soil through enhanced grass productivity and fire dynamics. However, the ecological benefits of such behaviours depend on population density and landscape context. While bulldozing vegetation may appear destructive, these behaviours often mimic natural disturbance regimes, promoting biodiversity and landscape heterogeneity, key components of climate-resilient ecosystems. Unlike anthropogenic clearing, elephant-led habitat modification is part of a long-evolved ecological process that supports nutrient cycling and seedling recruitment. Therefore, promoting connectivity through wildlife corridors supports not only elephant movement but also ecosystem functions that enhance resilience to climate variability. Future research should prioritise quantifying the net carbon impact of elephant movement and browsing in different biomes to further clarify their role in mitigating climate change. Conservation strategies informed by their movement patterns, such as wildlife corridors, conflict-reducing infrastructure, and habitat restoration, may enhance human–elephant coexistence while preserving their ecological roles. Protecting older individuals, who may retain critical environmental knowledge, is essential for sustaining elephant populations and the ecosystems they influence. Advancing research on elephant navigation and decision-making can provide valuable insights for biodiversity conservation and conflict mitigation efforts. Full article

Plant functional traits are indicative of the long-term responses and adaptations of plants to their environment. However, the specific mechanisms by which desert plant functional groups (PFGs) adjust their ecological adaptation strategies to cope with harsh environments remain unclear, particularly in ecologically fragile farming–pastoral zones. To address this gap, this study investigates and analyzes the morphological and chemical characteristics of 13 desert plant species in the farming–pastoral zone of the northern Tarim Basin. Through cluster analysis, these desert plants were categorized into distinct PFGs to elucidate their ecological response strategies at a higher organizational level. The results were as follows: (1) Based on plant functional traits, the 13 desert plant species were classified into acquisitive, medium, and conservative PFGs. These groups exhibited significant differences in chemical element content and proportion, as well as morphological adjustments (p < 0.05). (2) The acquisitive functional group maintained high resource acquisition and turnover through high specific leaf area and leaf phosphorus content; the medium functional group occupied limited resources through greater plant height and canopy width, whereas the conservative functional group exhibited low growth rates but high morphological investment to ensure survival. Moreover, these differences in ecological adaptation strategies led to the selection of divergent central traits by different PFGs. (3) Low soil nutrient availability and soil salinization, rather than groundwater depth, were identified as the primary environmental factors driving the differentiation of PFGs in the farming–pastoral zone. These findings suggest that desert plants in arid regions employ diverse ecological adaptation strategies to cope with environmental pressures. This research study provides valuable insights and recommendations for the conservation and restoration of desert plant communities. Full article

High-standing islands, such as Taiwan, offer unique opportunities to study soil organic carbon (SOC) dynamics due to their steep terrains, rapid erosion, and strong climatic gradients. In this study, we investigated 54 forest soil profiles across northern, central, and southern Taiwan to assess SOC inventories and turnover using stable carbon isotope (δ¹³C) analyses. We applied Rayleigh fractionation modeling to vertical δ¹³C enrichment patterns and derived the parameter β, which serves as a proxy for SOC turnover rates. Our findings reveal that SOC stocks increase notably with elevation, aligning with lower temperatures and reduced decomposition rates at higher altitudes. Conversely, mean annual precipitation (MAP) did not show a straightforward relationship with SOC stocks or β, highlighting the moderating effects of soil drainage, topography, and local hydrological conditions. Intriguingly, higher soil nitrogen levels were associated with a negative correlation to ln(β), underscoring the complex interplay between nutrient availability and SOC decomposition. Overall, temperature emerges as the dominant factor governing SOC turnover, indicating that ongoing and future warming could accelerate SOC losses, especially in cooler, high-elevation zones currently acting as stable carbon reservoirs. These insights underscore the need for models and management practices that account for intricate temperature, moisture, and nutrient controls on SOC stability, as well as the value of stable isotopic tools for evaluating soil carbon dynamics in mountainous environments. Full article

The use of plastic agricultural mulching films presents a “double-edged sword”: while these films enhance crop yields, they also lead to the accumulation of plastic film residues in the soil, creating new pollutants (microplastics). Our understanding of the “plastisphere”, a niche formed by agricultural film residues in the soil, where unique microbial communities and soil conditions converge remains limited. This is particularly true for protists, which are recognized as key determinants of soil health. Therefore, this study simulated a field experiment to analyze the effects of long-term plastic film residues on the structure of protist microbial communities in the rhizosphere, bulk soil and plastisphere of oilseed rape as well as their effects on soil nutrients. The results revealed that the residual plastic films underwent significant structural and chemical degradations. Protist diversity and co-occurrence network complexity were markedly reduced in plastisphere soils. In addition, soil moisture content, inorganic nitrogen and available phosphorus levels declined, leading to deficiencies in soil nutrients. Functional shifts in consumer protists and phototrophs along with weakened network interactions, have been identified as key drivers of impaired nutrient turnover. Our study underscores the critical role of protist communities in maintaining soil nutrient cycling and highlights the profound adverse effects of plastic film residues on soil ecosystems. These findings provide valuable insights into mitigating plastic residue accumulation to preserve long-term soil fertility and ensure sustainable agricultural productivity. Full article

Fine roots (diameter ≤ 2 mm) play a critical role in regulating soil organic carbon storage and nutrient cycling in forest ecosystems. However, the variability in fine root biomass, production, and turnover rates across different forest types remains poorly understood. This study investigates fine root dynamics, including biomass, distribution, and turnover, across four major monoculture plantation forests in subtropical China: Chinese fir (Cunninghamia lanceolata (Lamb.) Hook), Masson pine (Pinus massoniana Lamb.), Chinese sweet gum (Liquidambar formosana Hance), and camphor tree (Cinnamomum camphora (L.) J. Presl). Using a sequential coring method, soil samples were collected monthly to monitor live and dead fine root biomass across different soil depths (0–15 cm, 15–30 cm, 30–45 cm, and 45–60 cm). Fine root production and turnover rates were estimated using three methods: Max–Min, Integral and Decision Matrix. The results showed that fine root biomass was highest in the camphor tree forest (1.96 t ha⁻¹), followed by Masson pine (1.12 t ha⁻¹), Chinese fir (0.89 t ha⁻¹), and Chinese sweet gum (0.83 t ha⁻¹). Approximately 90% of the total fine root biomass was composed of live roots across all forest types, highlighting their significant role in nutrient uptake. Both live and dead fine roots were predominantly concentrated in the upper 0–30 cm soil layer, with a notable decline in biomass in deeper layers. Fine root biomass production was highest in the camphor tree forest (2.66–2.90 t ha⁻¹ a⁻¹), followed by Masson pine (1.16–1.83 t ha⁻¹ a⁻¹), Chinese fir (0.87–0.97 t ha⁻¹ a⁻¹), and Chinese sweet gum (0.87–0.93 t ha⁻¹ a⁻¹). Turnover rates were highest in the camphor tree forest (1.25–1.36 a⁻¹), followed by Masson pine (0.96–1.51 a⁻¹), and both Chinese fir and Chinese sweet gum (0.94–1.05 a⁻¹ and 0.97–1.04 a⁻¹, respectively). This study identifies significant differences in fine root dynamics among subtropical forest types, providing baseline data critical for optimizing forest management, particularly in urban and peri-urban areas. These insights can enhance reforestation efforts, ecosystem resilience, and sustainable forest productivity. Full article