Search Results (1,393)

In this study, we aimed to isolate indigenous plant-growth-promoting rhizobacteria (PGPR) with high indole-3-acetic acid (IAA)-producing capacity from alfalfa rhizospheres in arid regions of Northwest China and systematically evaluate their bioacceleration effects on alfalfa growth. Fifteen bacterial strains were isolated from rhizosphere soils collected in Ningxia and Inner Mongolia. Among them, four high-IAA-producing strains were selected and identified as Brevundimonas sp. B3, Pantoea sp. P10, and Microbacterium sp. M1 and M7 based on 16S rDNA sequencing. Pot experiments showed strain-specific growth-promoting effects: P10 significantly increased plant biomass (increasing fresh weight by 10.04% and dry weight by 11.76%, with p < 0.05), while M7 notably enhanced plant height (by 16.48%, with p < 0.05) and branching. Physiological and cytological analyses revealed that the tested strains improved chlorophyll content (30–45% above the control), reduced malondialdehyde (MDA) levels (20–40% below the control), and differentially regulated root-tip cell elongation. Principal component analysis further supported the comprehensive promotive effects of these strains, with P10 exhibiting the highest overall performance (PC1–PC4 cumulative variance: 83.1%). Within the limitations of controlled pot experiments, these findings highlight the potential of native PGPR strains, particularly P10 and M7, as promising candidates for developing region-specific microbial inoculants with which to enhance alfalfa productivity in arid and semi-arid environments. Full article

To investigate the key role of endophytic fungi in maintaining host adaptability and overall health, endophytic fungi were isolated from healthy root, stem and leaf tissues of Impatiens hawkeri, and the dominant strain FG8 with growth-promoting and antagonistic functions was screened. Strain FG8 was identified as Thelonectria veuillotiana by morphological and molecular biological methods. It exhibited an antifungal rate of 58.57% against Stagonosporopsis cucurbitacearum, the pathogen causing leaf spot disease of I. hawkeri. The broad-spectrum antifungal activity was verified by the plate confrontation method, and FG8 showed inhibitory effects on six common pathogenic fungi, with the highest inhibition rate of 64.5% against Apiospora intestini. Furthermore, strain FG8 displayed remarkable growth-promoting and antagonistic characteristics: it produced indole-3-acetic acid at 12.74 μg/mL, and possessed the abilities of phosphate solubilization, potassium mobilization, nitrogen fixation and siderophore synthesis. Its antagonistic activity was mediated by β-glucanase, amylase, cellulase and pectinase. Meanwhile, FG8 significantly induced the activities of four defensive enzymes in I. hawkeri, including superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and polyphenol oxidase (PPO). Seed growth-promotion experiments demonstrated that the root length, plant height, fresh weight and dry weight of seedlings in the FG8-treated group were significantly higher than those in the control group. These results indicate that strain FG8 has both growth-promoting and biological control functions, which can provide a potential resource for the biological control of I. hawkeri leaf spot and the development of fungal fertilizers. Its field application effect and mechanism of action need to be further explored. Full article

Axillary bud germination in sugarcane is a critical agronomic trait that directly determines seedling emergence and tillering capacity; however, its molecular regulatory mechanisms remain poorly understood. In this study, we systematically investigated the hormonal dynamics and transcriptomic profiles of the sugarcane cultivar XTT22 across five developmental stages (from dormancy to the first new leaf stage). Our results revealed that abscisic acid (ABA) content fluctuated during germination, whereas indole-3-acetic acid (IAA) and gibberellin (GA) levels decreased significantly, suggesting their negative regulatory roles. In contrast, cytokinin (CTK) and ethylene (ETH) contents increased at the initiation stage, indicating positive promoting functions. Transcriptome analysis identified 31,513 differentially expressed genes (DEGs), which were significantly enriched in pathways related to hormone signal transduction, starch/sucrose metabolism, and photosynthesis. Weighted gene co-expression network analysis (WGCNA) constructed 12 co-expression modules, among which the antiquewhite4 module (negatively correlated with IAA, GA, and ABA contents) and the darkorange2 module (positively correlated with cytokinin content) were identified as key regulatory modules. From these modules, seven core hub transcription factors (e.g., ScTCP5, ScSCR, and ScSHR1) were screened, and their expression patterns were validated by RT-qPCR. Furthermore, the expression trends of six hormone-related DEGs were highly consistent with the RNA-seq data. Collectively, this study elucidates the hormonal dynamics and gene regulatory networks underlying axillary bud germination in sugarcane, providing candidate gene resources for breeding high-yield varieties with enhanced emergence and tillering capacity. Full article

Patients with chronic kidney disease (CKD) have a markedly increased cardiovascular risk that is not fully explained by traditional risk factors. Gut-derived uremic toxins, indoxyl sulfate (IS), indole-3-acetic acid (IAA), and p-cresyl sulfate (pCS), are poorly cleared by dialysis and may contribute to vascular damage. This cross-sectional observational study included 70 patients with CKD under different clinical conditions (pre-dialysis, peritoneal dialysis, hemodialysis, and kidney transplantation) and 17 healthy controls. Serum levels of IS, IAA, pCS and Klotho were measured, and vascular damage was assessed by carotid intima–media thickness (IMT) using ultrasound. CKD patients showed higher concentrations of IS, IAA, and pCS compared with controls, with the highest levels observed in hemodialysis patients. Peritoneal dialysis was associated with elevated IS and pCS, whereas in kidney transplantation, IS and IAA levels did not differ significantly from controls, and pCS remained elevated. Carotid IMT was higher in patients with diabetes and those undergoing hemodialysis. IAA correlated significantly with left/mean IMT, and mean IMT was the only parameter associated with previous cardiovascular events. These findings suggest that gut-derived uremic toxins, particularly IAA, might be associated with subclinical vascular damage in advanced CKD, although larger studies are needed to confirm these associations. Full article

Nickel (Ni) contamination threatens plant growth and ecosystem stability, and plant-growth-promoting rhizobacteria (PGPR) are sustainable bioremediation candidates. Here, we isolated and characterized a Ni-resistant PGPR strain, Microbacterium algeriense C14, from the rhizosphere of Zinnia elegans in Ni-contaminated soil. C14 exhibited exceptional Ni tolerance (up to 800 mg·L⁻¹), produced indole-3-acetic acid (IAA), and maintained pH homeostasis (8.3–8.7). XPS and XRD analyses confirmed a novel carboxylate-based precipitation mechanism: C14 secretes carboxyl-containing metabolites that coordinate with Ni²⁺ to form stable amorphous nickel–carboxylate complexes. Under Ni stress (50–600 mg·L⁻¹ for germination; 50–600 mg·kg⁻¹ soil for pot experiments), C14 inoculation increased the seed germination index by up to 47.3%, seedling root length by 36.9%, and mature plant aboveground fresh weight by 21.32%, while reducing plant Ni uptake by 38.7% (seedlings) and 49.9% (mature shoots). It also enhanced plant antioxidant-enzyme (SOD and POD) activities and soluble protein content, improved soil quality (pH +0.16–0.33 units, urease/acid phosphatase activities elevated), and reduced soil-available Ni by 23.7%. Additionally, C14 enriched Proteobacteria in the rhizosphere and modified microbial community structure. These results highlight M. algeriense C14 as a promising resource for Ni-contaminated soil remediation via integrated metal immobilization, growth promotion, and rhizosphere regulation. Full article

Background: Gut microbiome-derived metabolites, particularly short-chain fatty acids (SCFA) and tryptophan derivatives, are central mediators of the gut–brain axis. This ex vivo study assessed how nutritional interventions impact such metabolites during early life, a critical period for neurodevelopment. Methods: The effects of galacto-oligosaccharides (GOS), nutrient blends (vitamins, minerals and amino acids) and their combinations were evaluated in the gut microbiomes of infants (2–4 months, n = 6) and young children (2–3 years old, n = 6) using the ex vivo SIFR^® technology. Results: Baseline microbiome composition was age-dependent, with infants displaying lower α-diversity and greater interpersonal variability. After ex vivo incubation, nutrient blends increased the propionate/butyrate ratio and branched-chain fatty acids in young children and elevated several B-vitamins and amino acid-derived metabolites, including indole-3-carboxaldehyde, imidazoleacetic acid and pipecolinic acid. Combining nutrient blends with GOS exhibited potential synergistic effects on propionate (infants) and 2-hydroxyisocaproic acid (HICA, both age groups). GOS strongly stimulated Bifidobacteriaceae and increased metabolites linked to bifidobacterial metabolism like acetate, HICA, N-acetylated amino acids, aromatic lactic acids and acetylagmatine; in young children, butyrate and γ-aminobutyric acid (GABA) also increased. Conclusions: Combinations of GOS with nutrient blends impacted microbiome-derived metabolites associated with the gut–brain axis, with potential synergistic increases of metabolites with emerging roles in neurodevelopment, including GABA, acetylagmatine and HICA. Despite shared bifidogenic effects, differences between age groups indicate that microbiome maturity may influence responses to nutritional intervention. Future clinical studies are needed to determine whether these metabolite changes translate into neurodevelopmental benefits in vivo. Full article

Excessive acidity restricts the utilization of citrus pulp, a major by-product of the dried tangerine peel industry. To overcome this bottleneck, a functional microbial consortium (BsHpMrF) comprising Bacillus subtilis L4, Hanseniaspora pseudoguilliermondii B4, and Monascus ruber CGMCC 10910 was constructed for efficient biological deacidification. The consortium exhibited a synergistic effect, achieving an 88.23% reduction in total acidity and converting the acidic pulp into a neutral, bio-stabilized substrate. Untargeted metabolomics analysis revealed that this efficiency was driven by the concurrent activation of the TCA cycle and glyoxylate shunt for organic acid mineralization, coupled with membrane lipid remodeling (increased unsaturation) to enhance acid tolerance. Notably, the fermentation process functioned as a “metabolic factory”, significantly enriching the matrix with bioactive lipids (e.g., 10-HDA, nervonic acid) and indole-3-acetic acid (IAA, 414.28 mg/L). Application assays demonstrated that the fermentation products acted as a potent biostimulant for soybean sprouts, significantly promoting lateral roots and eliciting the accumulation of antioxidant phenolics and flavonoids. This study provides a sustainable “waste-to-treasure” strategy, valorizing acidic citrus pulp into a functional biostimulant for high-quality edible sprout production, thereby achieving a sustainable “waste-to-food” circular loop. Full article

DREB (Dehydration-Responsive Element-Binding Protein) transcription factors are a subfamily of the AP2/ERF transcription factor family and play a crucial role in the regulation of plant responses to abiotic stress. In this study, we successfully cloned the IbDREB1d gene from the leafy sweet potato cultivar Fucaishu18. The open reading frame (ORF) of the IbDREB1d gene comprises 792 base pairs and encodes a protein consisting of 263 amino acids. Protein sequence analysis indicates that IbDREB1d is characterized by acidic, hydrophilic, and unstable properties, with its closest phylogenetic relationships to Ipomoea trifida and Ipomoea triloba. Quantitative real-time PCR (RT-qPCR) analysis revealed that IbDREB1d is expressed in the roots, stems, and leaves of sweet potato, with increased expression under low temperature, hydrogen peroxide (H₂O₂), and drought conditions. Overexpression of IbDREB1d in sweet potato resulted in transgenic plants exhibiting dwarfism, shortened internode lengths, smaller leaf size, and microscopic evidence of impaired vascular tissue development. Hormonal analysis indicated significant reductions in the levels of indole-3-acetic acid, indole-3-butyric acid, salicylic acid, and zeatin in these transgenic plants. These decreases may explain the observed phenotypic changes, such as inhibited growth and reduced leaf size. This study provides novel theoretical insights into the role of IbDREB1d in stress-responsive expression and modulating plant growth in sweet potato. Full article

Objectives: Allogeneic stem cell transplantation (HSCT) is curative in acute myeloid leukemia (AML) but is limited by relapse and non-relapse mortality (NRM). Metabolomic prognostic value is unclear. We assessed whether plasma metabolite profiles at diagnosis, pre-transplant, and post-transplant are associated with overall survival (OS) and cause-specific mortality. Methods: We retrospectively analyzed plasma metabolites from 63 AML patients undergoing HSCT (263 samples). Results: Higher levels of valine (hazard ratio [HR] 24.454), citrulline (HR 20.478), 5-oxoproline (HR 11.766), and glutamine (HR 8.701) associated with higher NRM, while inosine diphosphate (HR 0.091) and pyridoxamine-5′-phosphate (HR 0.313) associated with lower NRM. For relapse-related mortality (RRM), higher levels of phenylalanine (HR 26.585), leucine/isoleucine (HR 10.755), indolepyruvate (HR 7.676), and creatinine (HR 13.874) were associated with higher RRM, while trans-4-hydroxy-L-proline (HR 0.101) was associated with lower RRM. Higher post-transplant ornithine (HR 0.063), 3-sulfocatechol (HR 0.590), and indole-3-acetate (HR 0.359) were associated with improved OS. Mixed-effects modelling identified lower dehydroascorbate and citrate in relapsed patients, with dehydroascorbate remaining significant after false discovery rate adjustment. Conclusions: Metabolomic profiling nominated candidate metabolites for validation in larger prospective studies and elucidated mechanistic pathways, potentially informing novel interventions or risk-adapted monitoring strategies in HSCT. Full article

Garlic (Allium sativum L.) is an important vegetable with high nutritional and medicinal value. Its reliance on asexual reproduction causes variety degradation and low propagation efficiency, severely limiting the garlic industry. This study established an efficient shoot organogenesis system for the garlic cultivar Gailiangsuan through optimizing tissue culture protocols. Various explants, media, and hormone combinations were tested to determine the optimal conditions for improving in vitro propagation efficiency. The results demonstrated that for garlic inflorescence explants, immature inflorescences protruding 0–5 cm from the leaf sheath or not protruding were the optimal explants, exhibiting the highest shoot number. The Gamborg B5 (B₅) medium supplemented with a hormone combination of zeatin (ZT) 2 mg/L + indole-3-acetic acid (IAA) 0.05–0.2 mg/L at the first stage and ZT 0.2 mg/L + IAA 0.05 mg/L at the second stage was the most effective for improving in vitro propagation efficiency. For in vitro stem disc culture, the B₅ medium containing 6-benzylaminopurine (6–BA) 2 mg/L + 1-naphthaleneacetic acid (NAA) 0.2 mg/L was optimal. Moreover, a sucrose concentration of 7% was identified as optimal for microbulb development, resulting in significantly larger microbulbs than those grown in a medium with 3% sucrose. These results provide a technical basis for large-scale production of high-quality garlic seedlings. Full article

Seed priming is a simple, economical, and sustainable technique capable of enhancing crop resilience to abiotic stresses. A plastic greenhouse experiment was conducted on the durum wheat cultivar, Karim, sown in a 375 L volume container under semi-controlled conditions. Plots were arranged in a completely randomized design regarding treatments (control, salinity) and priming agents (indole-3-acetic acid, IAA; gibberellic acid, GA₃; and salicylic acid, SA). Some physiological, biochemical, and morphometric traits were analyzed at vegetative and reproductive stages. The obtained results demonstrated that salinity stress reduced plant growth and the SPAD index, hampered photosynthetic efficiency through disrupted PSII integrity and energy management in the electron transfer chain, and significantly affected ear filling (EF) and grain caliber (marked by mean weight of 100 grains, MW100G). However, seed hormonal priming allowed the alleviation of salinity stress effects on durum wheat growth and yield. Although IAA and GA₃ have shown significant potential in improving durum wheat tolerance to salinity, SA was found to be the most effective priming agent. It promotes the biosynthesis of chlorophyll pigments, restores the functional integrity of PSII, enhances photosynthetic efficiency, increases plant growth, and stimulates ear filling and wheat grain development. The principal component analysis demonstrated the interdependence of the vegetative and reproductive traits and presents SA as the most effective treatment that brings plants close to control conditions, despite the salinity. Full article

Maize (Zea mays L.) cultivation is severely affected by Fusarium verticillioides, a highly adaptable systemic pathogen that causes serious yield losses, reduces grain quality, and produces toxic fumonisin, posing significant health risks to humans and livestock. A biological control approach to combating it was investigated. Streptomyces sp. BPTC-684 showed strong inhibitory activity (53.11%) against F. verticillioides BNGO-16, isolated from a diseased tissue sample. Based on physiological and biochemical characteristics, 16S rRNA gene sequencing, average nucleotide identity, and digital DNA–DNA hybridization, strain BPTC-684 is considered a candidate new species belonging to the genus Streptomyces. In silico analysis of Streptomyces sp. BPTC-684 showed that it expresses diverse biosynthetic gene clusters encoding potential bioactive compounds, notably antibiotics (kinamycin, antimycin, fuelimycins A-C, hangtaimycin, and deoxyhangtaimycin) and siderophores (desferrioxamines B and E). In addition, plant growth-promoting behaviors, such as indole-3-acetic acid production; phosphate solubilization; and the production of extracellular lytic enzymes that degrade cellulose, chitin, proteins, amylose, and xylan, were also discovered in Streptomyces sp. BPTC-684. The pot experiments demonstrated that plant height, fresh weight, and dry root weight were increased in strain BPTC-684 by 37.88%, 132.50%, and 223.81%, respectively, compared to F. verticillioides BNGO-16 on the 15th day of infection. These findings suggest that Streptomyces sp. BPTC-684 is a promising biological control agent for inhibiting fungal diseases and promoting maize growth. Full article

Fusarium wilt, caused by Fusarium oxysporum f. sp. niveum (Fon), severely restricts the sustainable development of the global watermelon industry. While conventional chemical fungicides of this disease have triggered prominent ecological issues, Bacillus-based microbial biocontrol, which combines inherent environmental compatibility with stable control efficacy, has emerged as a key green alternative to chemical management. However, the biocontrol potential of Bacillus sonorensis against this disease has not yet been fully investigated. In this study, we isolated 56 bacterial strains from healthy watermelon rhizosphere soil, and obtained a Fon-antagonistic strain A-5 with the strongest activity (70.15% mycelial inhibition rate), which was identified as B. sonorensis via polyphasic taxonomic analysis. In vitro assays showed that the sterile fermentation filtrate of strain A-5 had a maximum 81.05% inhibition rate against Fon, and its volatile organic compounds also significantly suppressed Fon growth, with broad-spectrum antifungal activity against four common phytopathogenic fungi. Functional tests confirmed that strain A-5 could secrete cell wall-degrading enzymes, produce siderophores and synthesize indole-3-acetic acid, and 17 antimicrobial secondary metabolite biosynthetic gene clusters were identified in its genome. Pot experiments verified that strain A-5 had a 78.04% relative control efficacy against watermelon Fusarium wilt, which significantly reduced seedling disease incidence and upregulated defense-related antioxidant enzyme activities in watermelon leaves. In general, B. sonorensis A-5 is a promising novel biocontrol agent for green management of watermelon Fusarium wilt. Full article

Acute kidney injury (AKI) is a major complication of lupus nephritis and kidney transplantation, inevitably causing ischemia–reperfusion (I/R) injury. We previously confirmed that high-dose voclosporin induces drug nephropathy through aberrant peroxisome accumulation. The latter induces increased renal indole-3-aceticT acid (IAA) production due to the decreased expression of the IAA-degrading enzyme indolethylamine N-methyltransferase (INMT). Conversely, INMT overexpression prevents this nephropathy, suggesting that high-dose voclosporin could enable a novel therapeutic approach. This prompted us to test whether INMT overexpression with high-dose voclosporin could avert nephrotoxicity and protect against I/R injury. Inmt-overexpressing mice treated with high-dose voclosporin exhibited absence of peroxisomal abnormalities and resistance to I/R injury. RNA sequencing revealed the downregulation of tubular injury markers NGAL (Lcn2) and KIM-1 (Havcr1) concurrent with significant cytokine suppression. Mechanistic analysis revealed the robust induction of Regnase-2, an mRNA decay factor, which directly targeted stem–loop structures within the 3′ untranslated region of Lcn2 and Havcr1, thereby promoting their degradation in proximal tubular cells. Importantly, Regnase-2 knockdown mice showed Lcn2 upregulation, mitochondrial dysfunction, and peroxisomal abnormalities culminating in AKI, underscoring its renal protective effects. High-dose voclosporin under Inmt overexpression promoted Regnase-2-mediated mRNA decay to suppress tubular injury. This protective effect extended beyond I/R to rhabdomyolysis- and lipopolysaccharide-induced AKI to prevent nephropathy. Our findings demonstrate the potential transformative therapeutic approach of administering high-dose voclosporin to promote the prophylactic effect of Regnase-2 augmentation against AKI in both native and transplanted human kidneys. Full article

To explore the application potential of insect-derived functional microorganisms in short-cycle leafy vegetable production, we evaluated the effects of Serratia marcescens BRC-CXG2, isolated from larvae of Monochamus alternatus, on romaine lettuce in a pot experiment. Plant growth traits, biomass accumulation, nutritional quality, endogenous hormones, and rhizosphere microbial communities were systematically evaluated. The results demonstrated that inoculation significantly promoted seedling development. Plant height and root length increased by 48.7% and 29.1%, respectively, while shoot and root dry weights were 1.78- and 1.85-fold higher than those of the control. Vitamin C and total sugar contents increased by 76.4% and 98%, respectively. The levels of gibberellins (GA₃)-, indole-3-acetic acid (IAA)-, and abscisic acid (ABA)-immunoreactive equivalents increased by 1.5-, 1.29-, and 1.75-fold. High-throughput 16S rDNA gene and ITS amplicon sequencing further revealed that inoculation reshaped the composition of bacterial and fungal communities in the rhizosphere. Collectively, these findings demonstrate that insect-derived S. marcescens exhibits significant growth-promoting potential in short-cycle leafy vegetable systems, with effects associated with hormone regulation, enhanced total sugar accumulation, and shifts in rhizosphere microbial community structure. Full article