Search Results (269)

The increasing contamination of agricultural soils with microplastics (MPs) represents an emerging environmental challenge. While conventional plastics such as low-density polyethylene (LDPE) persist for decades, biodegradable alternatives like polybutylene adipate terephthalate (PBAT) are promoted as eco-friendly solutions. However, their environmental safety for crop plants and soil microbiota remains poorly understood. In this study, we evaluated the effects of LDPE and PBAT microplastics (1% w/w) on the growth and physiological state of winter wheat (Triticum aestivum L.) cultivated in soil, either alone or in combination with the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) and the plant-beneficial fungus Trichoderma citrinoviride. Growth parameters (root and shoot length and mass), germination index, chlorophyll content, antioxidant enzyme activity, and lipidomic profiles of wheat were assessed. PBAT stimulated biomass accumulation but simultaneously triggered oxidative stress and remodeled membrane phospholipids, indicating physiological disturbance. T. citrinoviride enhanced wheat growth and mitigated oxidative stress under non-contaminated conditions; however, its beneficial effect was generally suppressed in the presence of PBAT and/or 2,4-D. The results suggest that, despite its biodegradability, PBAT may pose a higher phytotoxic potential than conventional LDPE, particularly by altering oxidative balance and membrane lipid composition in wheat. Full article

Soil salinity is a major constraint on global crop production, disrupting photosynthesis, ion homeostasis, and growth. Beyond the roles of classic osmoprotectants and antioxidant enzymes, flavonoids have emerged as versatile mediators of salt stress tolerance at the interface of redox control, hormone signaling, and developmental plasticity. This review summarizes current evidence on how salinity remodels flavonoid biosynthesis, regulation, and function from cellular to whole-plant scales. We first outline the phenylpropanoid–flavonoid pathway, with emphasis on transcriptional control by MYB, bHLH, and NAC factors and their integration with ABA, JA, and auxin signaling. We then discussed how post-synthetic modifications such as glycosylation and methylation adjust flavonoid stability, compartmentation, and activity under salt stress. Functional sections highlight roles of flavonoids in ROS scavenging, Na⁺/K⁺ homeostasis, membrane integrity, and the modulation of ABA/MAPK/Ca²⁺ cascades and noncoding RNA networks. Spatial aspects, including root–shoot communication and rhizosphere microbiota recruitment, are also considered. Based on this synthesis, we propose a flavonoid-centered stress network (FCSN), in which specific flavonoids function as key nodes that connect metabolic flux with hormonal crosstalk and stress signaling pathways. We argue that reconceptualizing flavonoids as central stress network regulators, rather than generic antioxidants, provides a basis for metabolic engineering, bio-stimulant design, and breeding strategies aimed at improving crop performance on saline soils. Full article

This preliminary clinical study investigated the microbial composition of dental biofilms on healthy root surfaces and cavitated root caries lesions in two age cohorts: adults under 65 years and those aged 65 and older. The goal was to assess how aging and caries status influence root surface biofilm diversity and structure. For that, forty adults (23 women, 17 men) were enrolled. Biofilm samples were collected directly from clinically healthy and cavitated root surfaces. Microbial profiling was performed using 16S rRNA gene sequencing to evaluate diversity metrics and community composition. The results show that cavitated root surfaces harbored significantly higher microbial diversity compared to healthy root surfaces, as indicated by the Shannon diversity index. In contrast, healthy surfaces exhibited lower diversity and greater species dominance, confirmed by Simpson’s index. Age-related differences in biofilm composition were also evident, with older adults showing distinct microbial communities compared to younger participants. In conclusion, both age and cavitation presence significantly influence biofilm composition on root surfaces. These differences in microbial diversity and dominance may inform future clinical strategies for managing root caries, particularly in older adults. Further research is needed to assess the implications of these microbial patterns on treatment outcomes. Full article

Biostimulants boost plant growth, productivity, and nutrient retention, and can be produced from agri-food waste via microbial fermentation. In this study, undersized and unsold kiwifruits were fermented with Lactiplantibacillus plantarum to produce a fermented kiwifruit-based biostimulant (FKB). FKB was applied to soilless tomato plants (cv. Solarino) at two concentrations (50 and 100 mL L⁻¹) at the root level, every two weeks throughout the crop cycle. Fruits were analyzed for technological and chemical parameters, including color, texture, total soluble solids, titratable acidity, sugar/acid ratio, pH, electrical conductivity, total polyphenol content, antioxidant activity, and lycopene concentration. Additionally, metataxonomic analysis characterized the substrate microbial community at the beginning and the end of cultivation. Overall, the results indicate a dose-dependent effect of FKB on fruit quality parameters, with the highest concentration showing the most pronounced effects, specifically for the fruit firmness (8.02 N for FKB at 100 mL L⁻¹ vs. 7.25 N for the Control). Moreover, both tested concentrations were associated with increased antioxidant activity (on average +28%), and lycopene content (on average +57%) compared with the Control fruits. While overall microbial diversity remained largely unchanged, the relative abundance of bacterial taxa associated with nutrient cycling and plant–microbe interactions was modulated by the biostimulant, indicating subtle but potentially functionally relevant shifts in the rhizosphere microbiota. These findings suggest that fermented kiwifruit biomass can serve as an effective biostimulant, improving both fruit quality and the functional structure of the rhizosphere microbial community in soilless tomato cultivation. Full article

Long-term exposure of plastics to the environment causes them to disintegrate, resulting in the formation of micro/nanoplastics as well as the release of additives and chemicals into the soil. The micro/nanoplastics are able to readily migrate into the soil, destabilize the soil microbiota, and finally enter crop plants. Endocytosis, apoplastic transport, root adsorption, transpiration pull, stomatal entry, and crack-entry mode are well-known pathways by which microplastics enter into plants. Roots of vegetable crops were able to transfer 0.2 µm–1.0 µm of microplastics through root adsorption and by transpiration pull to the xylem and then further transported them to the plant tissues through apoplastic pathways. Beads of 1000 nm size were also engulfed by BY-2 protoplast cells through endocytosis. Micro and nanoplastics that enter crops affected the physiological and biochemical activities of the plants. Aquaporins were needed to aid the symplastic pathway which made the symplastic pathway difficult for MPs/NPs transport. Microplastics block seed capsules and roots of seedlings, thereby negatively affecting the uptake and efficient use of nutrients supplied. Photosynthesis of plants was affected due to the reduction in chlorophyll contents. Exposing soils to MPs/NPs drastically affected the pH, EC, and bulk density of the soil. This review focused on bridging the knowledge gap with understanding how microplastics prevent nutrient uptake and nutrient use efficiency in plants. This understanding is essential for assessing the broader ecological impacts of plastic contamination and for developing effective mitigation strategies. Further research is needed on microorganisms capable of degrading plastics, as well as on developing analytical methods for detecting plastics in soil and plant tissues. Also, further research on how to replace plastic mulching and still provide the same benefits as plastic mulch is needed. Full article

Alzheimer’s disease (AD), the leading cause of dementia worldwide, is characterized by progressive neuronal loss, amyloid-β (Aβ) aggregation, tau hyperphosphorylation, oxidative stress, neuroinflammation, cholinergic dysfunction, and gut–brain axis dysregulation. Despite advances in anti-amyloid therapeutics, current interventions provide only modest symptomatic relief and face limitations in accessibility, cost, and long-term efficacy. Plant-derived bioactive compounds, rooted in traditional medicine systems such as Ayurveda and Traditional Chinese Medicine, have gained increasing attention as multi-target therapeutic agents due to their pleiotropic actions, relative safety, and ability to cross the blood–brain barrier. This review synthesizes mechanistic and translational evidence on major phytochemicals, including withanolides (Withania somnifera), curcumin (Curcuma longa), ginkgolides and bilobalide (Ginkgo biloba), bacosides (Bacopa monnieri), ginsenosides (Panax ginseng), crocin/safranal (Crocus sativus), epigallocatechin-3-gallate (Camellia sinensis), rosmarinic acid (Salvia officinalis, Melissa officinalis), and asiaticosides (Centella asiatica). These compounds exert neuroprotective effects by inhibiting Aβ aggregation, reducing tau phosphorylation, scavenging reactive oxygen species, attenuating NF-κB-mediated inflammation, modulating cholinergic signaling, enhancing synaptic plasticity via brain-derived neurotrophic factor/cAMP response element-binding protein (BDNF/CREB) activation, and regulating gut microbiota. Multi-target approach analyses underscore their synergistic potential in targeting interconnected AD pathways. However, translation remains hindered by poor oral bioavailability, rapid metabolism, and variability in clinical outcomes. Advances in delivery platforms, including liposomes, bilosomes, solid lipid nanoparticles, and nanostructured lipid carriers, are improving stability, blood–brain penetration, and therapeutic efficacy in preclinical models. Collectively, plant-derived phytochemicals serve as promising, affordable, and multi-modal candidates for reshaping AD management, bridging traditional knowledge with modern therapeutic innovation. Full article

Chile, the leading exporter of cherries (Prunus avium L.) in the southern hemisphere, faces sustained variations in precipitation patterns and high evaporative demand in its productive areas. The low availability of water during the period of highest environmental demand makes it essential to reduce or suspend irrigation applications. In this scenario, regulated deficit irrigation (RDI) after harvest is an efficient strategy for optimizing water use without compromising orchard yields. This study was conducted over three consecutive seasons in a traditional commercial orchard of ‘Santina’ cherry trees grafted onto Colt rootstock, evaluating the effect of two levels of RDI, moderate (MDI) and severe (SDI), on productive and ecophysiological parameters. Both treatments resulted in water savings of between 10% and 28%, without negatively affecting yield or fruit quality. The SDI treatment, despite reaching higher levels of cumulative water stress, improved intrinsic water use efficiency while maintaining stable photosynthetic efficiency. In addition, an increase in the abundance of fine roots and beneficial rhizosphere bacteria populations, such as Azospirillum and Bacillus, was observed, suggesting the activation of water resilience mechanisms mediated by plant–microbiota interaction, possibly associated with stress-induced ecological memory and microbial legacy effects. These results position after-harvest RDI as a sustainable tool for coping with climate variability and water scarcity in commercial cherry orchards. Full article

Rhizosphere microbiota, serving as pivotal drivers of multifunctionality in grassland ecosystems, are jointly shaped by the dual influences of biotic and abiotic factors. Among biotic components, plant functional types selectively modulate microbial communities through root exudate specificity, while soil fauna (e.g., nematodes and earthworms) drive microbial interaction networks via biophysical disturbances and trophic cascades. However, excessive nematode grazing suppresses the hyphal extension of arbuscular mycorrhizal fungi (AMF). Moderate grazing facilitates the proliferation of ammonia-oxidizing bacteria through fecal input, whereas intensive grazing induces topsoil compaction, leading to a dramatic 40–60% reduction in lipopolysaccharide content in Gram-negative bacteria. Long-term chemical fertilization significantly decreases the fungal-to-bacterial ratio, while organic amendments enhance microbial carbon use efficiency by activating extracellular enzymatic activities. Regarding abiotic factors, the stoichiometric characteristics of soil carbon, nitrogen, and phosphorus directly regulate microbial metabolic strategies. Hydrological dynamics influence microbial respiratory pathways through oxygen partial pressure shifts—drought stress inhibits mycelial network development. Future research should focus on predicting the emissions of gases such as N₂O (ozone monomer) and optimizing nitrogen fertilizer management to significantly reduce greenhouse gas emissions at the source. The soil organic carbon storage in grassland ecosystems is extremely large. Effective prediction and management can make these soils become important carbon “sinks”, offsetting the carbon dioxide in the atmosphere. At the same time, transcriptomics and metabolic flux analysis should be combined with multi-omics technologies and in situ labeling methods to provide theoretical basis and technical support for developing mechanism-based and predictable grassland restoration and adaptive management strategies from both macroscopic and microscopic perspectives. Full article

Background/Objectives: Rheum officinale, an ethnomedicinal plant, has roots widely employed in modern pharmacological formulations. However, many of its biological activities remain only partly recognized. Furthermore, the metabolome and biological activity of its edible petioles, often considered a waste product, have received limited scientific attention. Methods and Results: The examination of anti-inflammatory properties of both root and petiole extracts (1–50 µg/mL) revealed the inhibition of the pro-inflammatory cytokine release from human peripheral blood mononuclear cells, a reduction in ALOX5 gene expression in human umbilical vein endothelial cells, and the significant inhibition (>60%) of cyclooxygenase-2 and 5-lipoxygenase activities. Importantly, no cytotoxic effects were detected at the tested concentrations. Conclusions: The petiole extract demonstrated anti-inflammatory efficiency comparable to, or exceeding that of the root extract, suggesting that R. officinale petioles could be valuable source of bioactive compounds for future investigations. Full article

Soil-borne diseases of banana severely threaten the sustainable development of the banana industry. In the pineapple–banana rotation system, using rhizosphere microorganisms to control banana Fusarium wilt via pineapple root exudates is a promising green control strategy. However, the role of volatile organic compounds (VOCs) in mediating disease suppression remains unclear. To explore the disease-inhibiting mechanisms, this study employed in vitro assays and high-throughput sequencing to evaluate the effects of three pineapple-root-derived VOCs (decanal, nonanal, octanol). The results showed the following: (1) All three VOCs strongly inhibited the mycelial growth of Fusarium, with octanol exhibiting the highest inhibition. (2) Each VOC promoted Arabidopsis thaliana growth, and decanal was the most effective. (3) In pot experiments, these VOCs significantly altered the banana rhizosphere microbial community, facilitating the colonization of beneficial genera—characterized by reduced microbial diversity and increased beneficial genera abundance. These results delineate a VOC-mediated rhizosphere microbe–Fusarium–plant interaction network, offering a novel theoretical foundation for the ecological control of banana diseases via the rhizosphere microbiome. In conclusion, this study elucidates a new mechanism for banana disease inhibition via VOCs, highlighting the positive impacts on plant growth and rhizosphere soil health through microbiota modulation. Full article

Kobresia humilis, an alpine meadow-constructive species, has significant ecological and economic importance on the Qinghai–Tibetan Plateau (QTP). Understanding the diversity and structure of the rhizosphere microbiota associated with K. humilis is essential for advancing microbiome engineering aimed at promoting sustainable ecosystem functioning in alpine meadows. However, little is known about the composition of bacterial community associated with K. humilis and the environmental drivers affecting microbiota assembly on a larger scale. This study revealed that bacterial communities inhabiting the rhizosphere exhibited greater diversity and higher compositional dissimilarity than those within the root compartment (ANOSIM, R = 0.86, p = 0.001). The bacterial genus Sphingomonas was identified as the predominant taxon in both microbial niches. A total of 196 and 176 core genera were detected in the roots and rhizosphere, respectively, with chemoheterotrophy and aerobic chemoheterotrophy representing the dominant functional groups. Co-occurrence network analysis identified hub genera, including Sphingomonas, Rhodomicrobium, Rhizobacter, and Phyllobacterium within root, and Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium, Acidibacter, RB41, and Sphingomonas in the rhizosphere. Among the sampling sites, Haiyan (HY) emerged as the central hub (EIC_HY = 1), followed by Tianjun (EIC_root = 0.98; EIC_soil = 0.99) and Xinghai (EIC_root = 0.97; EIC_soil = 0.95). Redundancy analysis indicated that bacterial abundance in roots was significantly influenced by geographic variables, temperature, and edaphic factors, whereas bacterial communities in the rhizosphere were primarily affected by latitude, altitude, pH, and climatic conditions (p < 0.05). Furthermore, the core bacterial genera exhibited stronger correlations with geographic and edaphic parameters than with climatic factors (p < 0.05). Collectively, these results enhance the current understanding of K. humilis–microbe–environment interactions within the alpine meadow ecosystems of the QTP. Full article

The use of bioinoculants aligns with ecological intensification in agriculture, but their effects on crop performance and soil microbiota under different fertilization regimes remain unclear. This study evaluated the impact of a bioinoculant containing two phosphate-solubilizing bacterial strains (Priestia megaterium and Bacillus subtilis) on maize yield, root architecture, and rhizosphere microbial communities via seed inoculation in a clayey soil. Maize was cultivated for two consecutive seasons under treatments combining inoculation, phosphorus sources (triple superphosphate or reactive rock phosphate), and P doses (0 or 120 kg ha⁻¹ of P₂O₅). Root traits, phosphatase activities, and microbial diversity were assessed at flowering, while agronomic parameters and nutrient content were measured at harvest. In the first season, microbial alpha diversity was higher, accompanied by a 31.5% increase in root surface area and a 46.2% increase in P-resin availability. In contrast, the second season showed greater phosphatase activity and higher grain P and K concentrations, by 42.3% and 38.2%, respectively. Grain yield did not differ significantly between inoculated and non-inoculated treatments; however, root, plant, and microbial traits varied markedly across seasons. Principal component analysis revealed that productivity was primarily driven by seasonal variation rather than by fertilization or inoculation. These findings emphasize that the effectiveness of bioinoculants and P fertilization, as well as their influence on the microbiota, are highly context-dependent, being shaped by environmental conditions, soil nutrient availability, and crop genotype. Full article

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

As an important complementation of plant genetic traits, seed endophytes (SEs) have garnered significant attention due to their crucial roles in plant germination and early seedling establishment. In this study, we employed both culture-dependent and amplicon sequencing-based approaches to characterize the endophytic microbiome in seed samples derived from different individual Panax notoginseng plants. Additionally, we evaluated the antagonistic activity of isolated culturable bacterial SEs against the root rot pathogens Fusarium solani and F. oxysporum. Our results demonstrated that a greater sampling quantity substantially increased the species richness (Observed OTUs) and diversity of seed endophytic microbiota, underscoring the importance of seed population size in facilitating the vertical transmission of diverse endophytes to progeny. The endophytic communities (including both fungi and bacteria) exhibited a conserved core microbiota alongside host-specific rare taxa, forming a phylogenetically and functionally diverse endophytic resource pool. Core bacterial genera included Streptococcus, Methylobacterium-Methylorubrum, Sphingomonas, Burkholderia-Caballeronia-Paraburkholderia, Pantoea, Halomonas, Acinetobacter, Pseudomonas, Vibrio, and Luteibacter, while core fungal genera comprised Davidiella, Thermomyces, Botryotinia, Myrothecium, Haematonectria, and Chaetomium. Among 256 isolated endophytic bacterial strains, 11 exhibited strong inhibitory effects on the mycelial growth of F. solani and F. oxysporum. Further evaluation revealed that two antagonistic strains, Bacillus cereus and B. toyonensis, significantly enhanced seed germination and plant growth in P. notoginseng, and effectively suppressed root rot disease in seedlings. These findings highlight the potential use of SEs as biocontrol agents and growth promoters in sustainable agriculture. Full article