Search Results (1,428)

Plant growth-promoting rhizobacteria (PGPR) employ various mechanisms to enhance plant development and growth as well as to mitigate environmental stress, including heavy metal contamination. Cadmium is a particularly severe stressor, toxic to both plants and soil microbiota. Mesembryanthemum crystallinum L. (the common ice plant), a fast-growing semi-halophyte, was previously investigated for phytoremediation potential towards saline environments and toxic metals, especially cadmium and chromium. The study was aimed at assessing whether bacteria isolated from the rhizosphere of M. crystallinum treated with Cd reveal growth-promoting traits and if the plant tolerance to Cd results from a synergistic action of the Cd/salt-resistant strains. The isolates demonstrated PGP characteristics, including nitrogen fixation, phosphate solubilization, and production of ammonia, indolyl-3-acetic acid (IAA), and siderophores. A microbial consortium consisting of these strains was developed and applied to pots with M. crystallinum. After a 14-day experiment, plant growth and Cd-accumulation potential were evaluated upon treatment with 1 mM or 10 mM Cd, either in the presence or absence of NaCl. Plant inoculation with the consortium stimulated Cd accumulation both by roots and shoots at 10 mM Cd under saline conditions. The results suggest that bioaugmentation of M. crystallinum with the bacterial community can be used as an effective, sustainable phytoremediation method for cadmium-contaminated soils. Full article

Lacticaseibacillus rhamnosus (Lbs. rhamnosus) is renowned for its tolerance to gastric acid and adaptability to bile and alkaline conditions, and is crucial for intestinal health and immune regulation. In this study, integrated transcriptomic and proteomic analyses were employed to elucidate the response mechanisms of Lbs. rhamnosus under osmotic stress, induced by exposure to 0.6 M sodium lactate, which elevates environmental osmotic pressure. It was shown that 792 differentially expressed genes and 138 differentially expressed proteins were detected in Lbs. rhamnosus ATCC 53103 treated with osmotic stress. The differential regulation of these genes/proteins mainly includes the inhibition of fatty acid metabolism with membrane structural remodeling (downregulation of the acetyl coenzyme A carboxylase family and fatty acid binding protein family expression), dynamic homeostasis of amino acid metabolism (restriction of the synthesis of histidine, cysteine, leucine, etc., and enhancement of the catabolism of lysine, tryptophan, etc.), and survival-oriented reconfiguration of carbohydrate metabolism (gene expression related to the glycolytic pathway increases, while gene expression related to the pentose phosphate pathway decreases). These synergistic alterations in metabolic regulation may facilitate the adaptive response of Lbs. rhamnosus ATCC 53103 to osmotic stress. Overall, our findings deepen the current understanding of the stress response mechanisms in lactic acid bacteria and offer novel insights into the survival strategies employed by Lbs. rhamnosus ATCC 53103 under hyperosmotic conditions. Full article

Background: The escalating global salinization poses a significant threat to agricultural productivity, necessitating a thorough understanding of plant responses to high salinity. Pea sprouts (Pisum sativum), a nutrient-rich crop increasingly cultivated in salinized regions, serve as an ideal model for such investigations due to their rapid growth cycle and documented sensitivity to ionic stress. Methods: In order to understand the response of pea sprouts in physiological regulation, redox-metabolic adjustments, and transcriptome reprogramming under salt stress, we investigated the effects of high salt concentrations on the ascorbic acid–glutathione cycle, endogenous hormone levels, metabolite profiles, and gene expression patterns in it. Results: Our findings reveal early-phase antioxidant/hormonal adjustments, mid-phase metabolic shifts, and late-phase transcriptomic reprogramming of pea sprouts under salt conditions. In addition, a biphasic response in the ascorbic acid cycle was found, with initial increases in enzyme activities followed by a decline, suggesting a temporary enhancement of antioxidant defenses. Hormonal profiling indicated a significant increase in abscisic acid (ABA) and jasmonic acid (JA), paralleled by a decrease in indole acetic acid (IAA) and dihydrozeatin (DZ), underscoring the role of hormonal regulation in stress adaptation. Metabolomic analysis uncovered salt-induced perturbations in sugars, amino acids, and organic acids, reflecting the metabolic reconfiguration necessary for osmotic adjustment and energy reallocation. Transcriptomic analysis identified 6219 differentially expressed genes (DEGs), with a focus on photosynthesis, hormone signaling, and stress-responsive pathways, providing insights into the molecular underpinnings of salt tolerance. Conclusions: This comprehensive study offers novel insights into the complex mechanisms employed by pea sprouts to combat salinity stress, contributing to the understanding of plant salt tolerance and potentially guiding the development of salt-resistant crop varieties. Full article

Background: DNA methylation, as an epigenetic modification, is crucial in the regulatory mechanism of salt resistance in plants. Methods: To gain deeper insight into the relationship between DNA methylation and mRNA exons in halophytes and their potential roles in regulating salt tolerance, this study employed whole-genome bisulfite sequencing (WGBS) and transcriptome sequencing data to analyze the leaves of the halophyte Paspalum vaginatum, widely distributed in tropical regions. Results: The findings revealed that the methylation level of 5-methylcytosine (5mC) in the genomic elements of P. vaginatum increased with prolonged salt treatment under salt stress conditions. This observation suggested that the methylation level plays a pivotal role in the salt stress response of P. vaginatum. Notably, under salt stress, the number of variants at the mRNA exon level was significantly higher than that at the DNA level. Furthermore, comparative analysis revealed sequence variants within exonic regions of mature mRNA transcripts for several genes in salt-treated samples relative to pre-stress controls, and these changes were found to be enriched in several salt-tolerance pathways, including unsaturated fatty acid metabolism and ascorbic acid metabolism, among others. Further analysis demonstrated that the occurrence of these variants changed concomitantly with the dynamic changes in CG methylation levels in the gene body of some salt-tolerant genes. Therefore, it was speculated that mRNA exon variations probably promoted the elevation of CG 5mC methylation levels at the DNA level under salt stress conditions, further enabling the plant to adapt to the salt-stress environment. Conclusions: These findings offer preliminary insights into the relationship between DNA methylation and mRNA exon variations in P. vaginatum under salt stress, providing valuable information and avenues for further investigation into the regulatory role of mRNA in DNA methylation. Full article

Esophageal squamous cell carcinoma (ESCC) accounts for the majority of esophageal cancers worldwide, with a poor prognosis and increasing resistance to conventional treatments. Faced with these limitations, nanoparticles (NPs) are attracting growing interest as innovative therapeutic agents capable of improving specificity and efficacy and reducing systemic toxicity. This study critically examines the pharmacological effects, mechanisms of action, and toxicity profiles of different metallic or organic nanoparticles tested on ESCC cell lines. Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 guidelines were followed by a meticulous literature search of Google Scholar, Web of Science, PubMed/Medline, and Scopus databases to achieve this goal. The results show that the anti-tumor properties vary according to the type of nanoparticle (copper(II) oxide (CuO), silver (Ag), gold (Au), nickel(II) oxide (NiO), nano-curcumin, etc.), the synthesis method (chemical vs. green), and the biological activity assessment method (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), Bromodeoxyuridine (BrdU), Cell Counting Kit-8 (CCK8) assays, etc.). NPs derived from green synthesis, such as those based on Moringa oleifera, Photinia glabra, or pomegranate bark, exhibit moderate cytotoxic activity (50% inhibitory concentration (IC₅₀) between 92 and 500 µg/mL) but show good tolerance on normal cells. In contrast, chemically synthesized NPs, such as Cu(II) complexes with 1,3,5-benzenetricarboxylic acid (H₃btc) or 1,2,4-triazole (Htrz), show lower IC₅₀ (34–86 µM), indicating more marked cytotoxicity towards cancer cells, although data on their toxicity are sometimes lacking. In addition, multifunctional nanoparticles, such as gold-based nano-conjugates targeting Cluster of Differentiation 271 (CD271) or systems combined with doxorubicin, show remarkable activity with IC₅₀ below 3 µM and enhanced tumor selectivity, positioning them among the most promising candidates for future clinical application against ESCC. The most frequently observed mechanisms of action include induction of apoptosis (↑caspases, ↑p53, ↓Bcl-2), oxidative stress, and inhibition of proliferation. In conclusion, this work identifies several promising nanoparticles (silver nanoparticles derived from Photinia glabra (PG), gold-based nano-immunoconjugates targeting CD271, and silver–doxorubicin complexes) for future pharmaceutical exploitation against ESCC. However, major limitations remain, such as the lack of methodological standardization, insufficient in vivo and clinical studies, and poor industrial transposability. Future prospects include the development of multifunctional nanocomposites, the integration of biomarkers for personalized targeting, and long-term toxicological assessment. Full article

Arid and semi-arid regions show distinctive bacterial groups important for the sustainability of ecosystems and soil health. This study aims to investigate how environmental factors across five Qatari soils influence the taxonomic composition of bacterial communities and their predicted functional roles using 16S rRNA amplicon sequencing and soil chemical analysis. Soil samples from five different locations in Qatar (three coastal and two inland) identified 26 bacterial phyla, which were dominated by Actinomycetota (35–43%), Pseudomonadota (12–16%), and Acidobacteriota (4–13%). Species-level analysis discovered taxa such as Rubrobacter tropicus, Longimicrobium terrae, Gaiella occulta, Kallotenue papyrolyticum, and Sphingomonas jaspsi, suggesting the presence of possible novel microbial families. The functional predictions showed development in pathways related to amino acid metabolism, carbohydrate metabolism, and stress tolerance. In addition, heavy-metal-related taxa, which are known to harbor genes for metal resistance mechanisms including efflux pumps, metal chelation, and oxidative stress tolerance. The presence of Streptomyces, Pseudomonas, and Bacillus highlights their roles in stress tolerance, biodegradation, and metabolite production. These findings improve the understanding of microbial roles in dry soils, especially in nutrient cycling and ecosystem resilience. They highlight the importance of local bacteria for sustaining desert soil functions. Further research is needed to validate these relationships, using metabolomic approaches while monitoring microbial-community-changing aspects under fluctuating environmental conditions. Full article

Copper (Cu) is an essential micronutrient for plants, playing a crucial role in various physiological and molecular processes. Excess Cu induces oxidative stress and disrupts cellular functions, while Cu deficiency causes chlorosis and poor pollen development, thereby reducing crop yields. However, the molecular and evolutionary mechanisms of Cu tolerance and homeostasis remain unclear in the plant kingdom. In this review, we discuss the uptake, transport, and detoxification of Cu through high-affinity Cu transporters (COPTs). Additionally, we update recent studies on maintaining Cu balance by mediating the root exudation of organic acids (e.g., citrate and proline), xylem/phloem loading, cell wall binding, vacuolar sequestration, redistribution, and the activity of antioxidant enzymes (e.g., SOD, CAT, and APX). Furthermore, tissue-specific expression analyses reveal that COPT genes exhibit distinct spatial regulation in the roots and leaves, which are the primary sites of Cu transport and detoxification. Overall, our review highlights the critical roles of COPT gene families and detoxification pathways in maintaining Cu homeostasis in plants. Future research should focus on genetic engineering approaches to enhance Cu tolerance, optimize Cu distribution in grains, and mitigate soil contamination risks. By clarifying these mechanisms, we can develop strategies to sustain crop production under increasing Cu stress, thereby ensuring food security and human health. Full article

Chronic kidney disease (CKD) is a fast-growing cause of death worldwide. Systemic hypertension and diabetes mellitus are the major causes of kidney damage leading to a reduction in glomerular filtration rate and to urinary protein loss. Sodium–glucose cotransporter 2 inhibitors (SGLT2is) are drugs able to address both of these deleterious effects, preventing kidney damage from progressing. Initially born as hypoglycemic agents, SGLT2is subsequently proved to have not only positive metabolic but also pleiotropic effects on the kidney and the cardiovascular system. Indeed, they improve the metabolic profile, reducing uric acid, blood sugar levels, and body weight. Moreover, they exert an anti-inflammatory and antifibrotic effect, reducing endothelial dysfunction and reactive oxygen species (ROS) production. Finally, they reduce renal hyperfiltration and control blood pressure, inducing osmotic diuresis and restoring tubulo-glomerular feedback. All these metabolic, anti-inflammatory, and hemodynamic effects contribute to significantly reducing the risk of cardiorenal events, as widely demonstrated in randomized clinical trials. The pleiotropic actions of SGLT2is together with their good tolerability make them a pillar treatment of CKD regardless of the presence of diabetes mellitus. Further studies will be needed in order to expand the indications to populations previously excluded from clinical trials such as transplant recipients or glomerulonephritis patients. This narrative review aims to summarize current knowledge regarding the nephroprotective mechanisms of SGLT2is which, after initial use as a hypoglycemic agent, have assumed a pivotal role in the actual and future management of patients with CKD. Full article

Soil salinity severely impairs crop productivity by inducing osmotic stress, ionic toxicity, and oxidative damage. This study investigated the mechanisms by which foliar-applied wood vinegar (WV), a biomass pyrolysis byproduct rich in organic acids and minerals, alleviates salt stress (100 mM NaCl) in hydroponically grown wheat (Triticum aestivum L.). Three WV dilutions (100×, 300×, 500×) were tested to evaluate their effects on growth, antioxidant systems, chlorophyll metabolism, and ion homeostasis. The results demonstrated that 300×-diluted WV (WV3) most effectively mitigated salt stress, increasing shoot biomass by 81% and root length by 75% compared to salt-stressed controls. WV3 restored antioxidant enzyme activities to non-stressed levels, reduced lipid peroxidation, and normalized chlorophyll overaccumulation induced by salinity. Elemental profiling revealed that WV3 enhanced shoot K⁺ and Ca²⁺ uptake while reducing Na⁺ accumulation, thereby improving ion homeostasis. Additionally, WV3 promoted Fe translocation to shoots, supporting chlorophyll synthesis. However, 100× WV (WV1) exhibited phytotoxicity due to excessive organic acids, while 500× (WV5) showed limited efficacy. These findings highlight a 300-fold diluted solution of WV as an optimal dilution for enhancing wheat salt tolerance through coordinated ROS scavenging, photosynthetic protection, and ion regulation. This study provides a scientific basis for integrating WV into sustainable strategies to combat salinity in wheat cultivation. Full article

Aluminum (Al) toxicity in acidic soils severely limits the productivity of Chinese fir (Cunninghamia lanceolata) plantations. Despite being a crucial timber species in southern China, the regulatory mechanisms underlying phenolic accumulation and Al tolerance pathways under Al stress in Chinese fir remain unidentified. In this study, 5-month-old Chinese fir seedlings were treated with an exogenous phenolic synthesis inhibitor (AIP) and precursor (MJ) to establish the following groups: CK, AIP, MJ, Al, Al+AIP, and Al+MJ. Physiological and biochemical indicator analyses, transcriptome analysis, and protein interaction network predictions were conducted. The findings revealed that phenolic compounds enhance Al tolerance in Chinese fir through two mechanisms: (1) regulation of active oxygen homeostasis (elevating SOD and POD activities, promoting AsA and GSH accumulation, and augmenting total antioxidant capacity); and (2) modulation of cell wall characteristics (increasing pectin content and pectinase activity, and facilitating Al sequestration in the cell wall). Moreover, MJ was found to synergistically enhance these processes, while AIP impeded them. Genes associated with antioxidant enzymes, secondary metabolite synthesis, and cell wall modification were implicated in the regulatory mechanisms. This study provides a theoretical foundation for elucidating the adaptation of Chinese fir to Al toxicity in acidic soil environments, offers insights for enhancing Chinese fir productivity in acidic soils, and presents a novel target for breeding trees with stress resistance. Full article

In recent years, high temperature and drought have severely impacted the growth and development of loquat [Eriobotrya japonica (Thunb.) Lindl.] plants. Although dopamine can improve the stress resistance of plants, its role in combined stress requires further exploration. This study investigated the alleviative effect and mechanism of exogenous dopamine on loquat seedlings subjected to the combined stress of high temperature and drought. The combined stress significantly reduced root viability, photosynthetic pigment content, and net photosynthetic rate (Pn) while markedly increasing reactive oxygen species (ROS) levels, thiobarbituric acid-reactive substances (TBARS) content, and electrolyte leakage (EL). The seedlings exhibited pronounced wilting symptoms, along with markedly reduced root surface area and volume. Dopamine treatment significantly alleviated combined stress-induced damage. This mitigation was manifested through substantially enhanced root viability, photosynthetic pigment content, Pn, antioxidant enzyme activities, and osmotic adjustment substances concomitantly with marked reductions in ROS, TBARS content, and EL. Dopamine significantly reduced seedling wilting severity and improved root morphological parameters. This study demonstrates that dopamine enhances loquat seedlings’ tolerance to combined stress through coordinated mechanisms: maintaining photosynthetic pigments and improving stomatal conductance to sustain photosynthetic efficiency, enhancing antioxidant enzyme activity and ROS scavenging capacity to mitigate oxidative damage, and promoting osmotic solute accumulation for osmotic potential regulation. Full article

Polyamines (PAs), including putrescine, spermidine, spermine, and thermospermine, play essential roles in plant growth, development, and responses to stress. However, the structure and function of PA biosynthetic genes in pepper remain poorly characterized. This study aimed to identify PA biosynthesis genes in the pepper genome using bioinformatics approaches and to assess their expression under various stress conditions. A total of 16 PA biosynthesis-related genes were identified, representing members of the arginine decarboxylase (ADC), ornithine decarboxylase (ODC), agmatine iminohydrolase (AIH), N-carbamoylputrescine amidohydrolase (CPA), S-adenosylmethionine decarboxylase (SAMDC), spermidine synthase (SPDS), spermine synthase (SPMS), and ACAULIS5 (ACL5) gene families. These genes encode proteins with an average molecular weight of approximately 40 kDa, primarily localized in the mitochondria and cytoplasm. Promoter analysis revealed multiple cis-acting elements associated with stress and phytohormone responsiveness. Gene expression was induced by various abiotic stresses, including saline-alkaline, drought, heat, cold, and hydrogen peroxide, as well as by phytohormones such as abscisic acid, ethylene, salicylic acid, auxin, and gibberellin. Overall, this study provides a comprehensive analysis of PA biosynthesis genes in pepper and highlights their potential roles in stress adaptation and hormone signalling, offering a foundation for further exploration of PA-mediated stress tolerance mechanisms. Full article

Drought stress poses a significant threat to tree growth, making the development of drought-resistant species essential for ecological restoration. WRKY transcription factors are critical regulators of plant drought responses; however, the role of WRKY22 in the woody species Populus ussuriensis K. remains unclear. In this study, the PuWRKY22 gene was cloned from P. ussuriensis via homologous cloning and was found to be highly expressed in leaves and responsive to abscisic acid (ABA) signaling. Subcellular localization confirmed that PuWRKY22 is a nuclear protein. Using fluorescein enzyme complementation assays, PuWRKY22 was shown to bind specifically to W-box cis-elements, indicating its function as a transcriptional regulator. Under ABA and osmotic (sorbitol) stress, the seed germination rate, root growth, and biomass of tobacco and Populus davidiana × Populus bolleana strains overexpressing PuWRKY22 were significantly increased. Additionally, these overexpressed strains exhibited a reduction in reactive oxygen species (ROS) accumulation and a decrease in membrane lipid peroxidation. Transcriptomic analyses revealed that PuWRKY22 activates expression of the ABA receptor gene Ptr.PYL4 (Potri.006G104100.v4.1), which regulates stomatal closure to minimize water loss. Consistent with this, stomatal observations and photosynthetic measurements demonstrated that PuWRKY22 enhances drought tolerance by protecting photosystem II and preserving chlorophyll content. Collectively, this study elucidates the molecular mechanism by which PuWRKY22 enhances drought resistance in woody plants through ABA signaling, providing a foundation for breeding drought-tolerant forest species. Full article

Phthalic acid esters (PAEs), ubiquitously employed as a plasticizer, have been classified as priority environmental pollutants because of their persistence, bioaccumulation, and endocrine-disrupting properties. As a characterized PAE-degrading strain of marine origin, Mycolicibacterium phocaicum RL-HY01 utilizes di-(2-ethylhexyl) phthalate (DEHP) as its sole carbon and energy source. Genome sequencing and RT-qPCR analysis revealed a previously uncharacterized hydrolase gene (dehpH) in strain RL-HY01, which catalyzes ester bond cleavage in PAEs. Subsequently, recombinant expression of the cloned dehpH gene from strain RL-HY01 was established in Escherichia coli BL21(DE3). The purified recombinant DehpH exhibited optimal activity at 30 °C and pH 8.0. Its activity was enhanced by Co²⁺ and tolerant to most metal ions but strongly inhibited by EDTA, SDS, and PMSF. Organic solvents (Tween-80, Triton X-100, methanol, ethanol, isopropanol, acetone, acetonitrile, ethyl acetate, and n-hexane) showed minimal impact. Substrate specificity assay indicated that DehpH could efficiently degrade the short and long side-chain PAEs but failed to hydrolyze the cyclic side-chain PAE (DCHP). The kinetics parameters for the hydrolysis of DEHP were determined under the optimized conditions, and DehpH had a V_max of 0.047 ± 0.002 μmol/L/min, K_m of 462 ± 50 μmol/L, and k_cat of 3.07 s⁻¹. Computational prediction through structural modeling and docking identified the active site, with mutagenesis studies confirming Ser228, Asp324, and His354 as functionally indispensable residues forming the catalytic triad. The identification and characterization of DehpH provided novel insights into the mechanism of DEHP biodegradation and might promote the application of the target enzyme. Full article

The growing demand for sustainable and antibiotic-free animal production has intensified interest in probiotics as functional feed additives. In this study, novel strains of Weizmannia coagulans (WC412 and WC413) were isolated from pickle water—a previously unexplored source for probiotic screening. These isolates, along with three reference strains (W. coagulans S8, S15, and S17), were evaluated for their tolerance to heat, acid, and bile salts. Strain WC412 exhibited superior environmental resilience, as validated by principal component analysis (PCA) for comprehensive stress-tolerance assessment, and was selected for further investigations. A murine model was employed to assess the physiological and microbiological impacts of WC412 supplementation at varying doses. Medium-dose (1 × 10⁷ CFU·mL⁻¹) administration significantly improved body weight gain by 13% (p < 0.05), modulated serum lipid profiles, and increased antioxidant enzyme activity and IgG/IL-2 levels (p < 0.05). Notably, WC412 uniquely enriched beneficial genera (e.g., Fructilactobacillus and Limosilactobacillus) and promoted metabolic pathways linked to short-chain fatty acid production, as revealed by 16S rDNA sequencing and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. These findings highlight WC412 as a robust probiotic candidate for enhancing animal growth performance and gut health through novel microbiota-mediated mechanisms. Full article