Search Results (1,291)

The excessive use of chemical fertilizers raised concerns regarding environmental sustainability and soil degradation, prompting increasing interest in biofertilizers as eco-friendly alternatives. Among these, a compound that is effective in stimulating root and plant growth is indole-3-acetic acid (IAA). In our study, we evaluated IAA production by the halotolerant bacterium Vreelandella titanicae under different and varying nutritional conditions, such as tryptophan availability, temperature, pH, salinity, etc. The bacterium showed significant IAA production under a broad range of conditions and a dependence on the presence of tryptophan for IAA biosynthesis. High salinity (1.0 M NaCl), slightly alkaline pH (8.0–9.0), and temperatures of 34 °C increased IAA production, while optimal growth occurred in the absence of NaCl at a range of temperatures of 25–28 °C, suggesting a stress-responsive regulation of its biosynthesis. Easily metabolizable carbon sources, such as glucose and mannitol, enhanced IAA yield again, whereas additions of 1.0 g L⁻¹ NH₄NO₃ and KH₂PO₄ in the basal medium, poor in these salts, inhibited both the growth of the bacterium and IAA production. Notably, V. titanicae produced relevant amounts of IAA in seawater (24.57 ± 11.28 μg⋅mL⁻¹) when used as growth medium and dairy whey (15.68 ± 2.42 μg⋅mL⁻¹), highlighting its suitability for low-cost and circular bioprocessing strategies. In conclusion, V. titanicae is a promising Plant Growth-Promoting Rhizobacterium (PGPR) candidate for sustainable IAA production and potential application in saline or marginal agricultural soils. Its ability to synthesize IAA in different growth media could allow its exploitation in environmentally friendly bioprocesses. Full article

Brachiaria decumbens is a high-yielding forage grass of major economic value in tropical regions. The root endophytic fungus Piriformospora indica is widely recognized for promoting plant growth and stress tolerance, yet its effects on B. decumbens remain poorly characterized. Here, we profiled root responses to P. indica colonization at 10 days after inoculation (dais; early stage) and 20 dais (late stage) during symbiosis establishment. Colonization was confirmed by phenotypic and physiological assessments, with inoculated plants showing enhanced root growth; colonized roots exhibited higher activities of catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD), along with increased indole-3-acetic acid (IAA) levels, whereas malondialdehyde (MDA), jasmonic acid (JA), and the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) were reduced. Transcriptome and metabolomic profiling identified 1884 and 1077 differentially expressed genes (DEGs) and 2098 and 1509 differentially accumulated metabolites (DAMs) at 10 dais (Pi10d vs. CK10d) and 20 dais (Pi20d vs. CK20d), respectively, and 3355 DEGs and 2314 DAMs between stages (Pi20d vs. Pi10d). Functional enrichment highlighted key pathways related to secondary metabolism, carbohydrate metabolism, and lipid biosynthesis. Differentially expressed transcription factors spanned multiple families, including MYB, AP2/ERF, MADS-box, and bZIP, consistent with broad transcriptional reprogramming during symbiosis establishment. Integrative multi-omics analysis further highlighted phenylpropanoid biosynthesis and α-linolenic acid metabolism as consistently co-enriched pathways, suggesting coordinated shifts in gene expression and metabolite accumulation across colonization stages. Collectively, these results provide a multi-layered resource and a framework for mechanistic dissection of the P. indica–B. decumbens interaction. Full article

Seed vigor is a key agronomic trait that integrates germination capacity and seedling establishment, critically influencing rice productivity. Inositol hexakisphosphate (IP₆) serves as a major phosphorus reservoir in seeds, yet its regulatory mechanism in seed vigor remains unclear. Here, we demonstrate that exogenous IP₆ application inhibited seed germination and seedling growth of japonica rice (Oryza sativa L. ssp. japonica cv. Zhonghua11) in a dose-dependent manner; 10 mM IP₆ reduced seed germination by 100%, while 100 μM IP₆ suppressed primary root length by 33.6% compared to the control. This inhibitory effect is likely mediated by antagonizing auxin signaling, as supported by suppressed DR5::GUS expression and altered transcription of auxin-responsive genes. OsIPK2, a key enzyme in IP₆ biosynthesis, showed high expression during early development in rice. RNA interference of OsIPK2 led to a 40.8–61.7% reduction in seed IP₆ content, 45.3–65% higher zinc (Zn) and iron (Fe) accumulation, and a 35.4–53.5% lower germination rate compared to wild-type (WT). Conversely, OsIPK2-RNAi seedlings exhibited enhanced growth and resistance to IP₆, which was associated with misregulation of auxin-responsive genes and a decrease in the repressive histone mark H3K27me3 at their loci. Furthermore, endogenous indole-3-acetic acid (IAA) levels significantly reduced in Ri-1 but unchanged in Ri-2, while abscisic acid (ABA) content and the IAA/ABA ratio remained unaltered compared to wild-type. Our findings reveal that OsIPK2 balances seed vigor and seedling development by modulating inositol phosphate metabolism, auxin responses, and epigenetic regulation, providing insights for improving seed quality in cereals. Whether the regulatory role of OsIPK2 in seed vigor is conserved across other rice subspecies requires further investigation. Full article

P-cresol, indole and indole-3-acetic acid (IAA) are catabolites of amino acids, formed by the gut microbiome. Most of these aromatic hydrocarbon derivatives are excreted by the colon before reentering the body to form “exogenous” protein-bound uremic toxins (PBUTs), which aggravate chronic kidney disease (CKD). Removal efficiencies of these PBUT precursors from model phosphate-buffered saline solutions by three different surface-modified nanoporous carbon adsorbents (PCs) were studied. PCs were produced by physicochemical and/or acid base activation of carbonized rice husk waste. Removal rates achieved values of 32–96% within a 3 h contact time. High micro/mesoporosity and surface chemistry of the N- and P-doped biochars were established by N₂ adsorption studies, SEM/EDS analysis, XPS and FT-IR-spectroscopy. The ammoxidized PC-N1 had the highest adsorption capacity (1.97 mmol/g for IAA, 2.43 mmol/g for p-cresol and 2.42 mmol/g for indole), followed by “urea-nitrified” PC-N2, whilst the phosphorylated PC-P demonstrated the lowest adsorption capacity for these solutes. These results do not correlate with the total pore volume values for PC-N2 (0.91 cm³/g) < PC-P (1.56 cm³/g) < PC-N1 (1.84 cm³/g), suggesting that other parameters such as the micropore volume (PC-N1 > PC-N2 > PC-P) and the interaction of surface chemical functional groups with the solutes play key roles in the adsorption mechanism. N-doped PC-N1 and PC-N2 have basic functional groups with higher affinity with acidic IAA and p-cresol. The ion-exchange mechanism of phenolic and indolic compound chemisorption by nanoporous carbon adsorbents, modified with surface N- and P-containing functional groups, has been proposed. Full article

In recent years, the incidence of breast cancer has increased significantly; therefore, much attention is being paid to research on natural plant-based raw materials in the treatment and prevention of cancer as well as in the treatment of antibiotic-resistant infections. Therefore, Chlorella vulgaris algae extract and indole-3-acetic acid (IAA)—a plant hormone with potential anticancer and antimicrobial properties—were selected for the study. The main objective was to evaluate the effect of algae extract and IAA on the proliferation of cells from three different breast cancer lines: MCF-7, ZR-75-1, and MDA-MB-231. In addition, an analysis of apoptosis and oxidative stress parameters in cancer cells was performed, as well as an assessment of IAA toxicity towards E. coli, S. aureus, and C. albicans. The results obtained allow us to conclude that the extract is effective against estrogen-dependent cells, while the effect of IAA alone varies depending on the microorganism studied, the cell line analyzed, and the concentration used. The extract in selected concentrations induces apoptosis and activates oxidative stress mechanisms, while IAA exhibits cytotoxicity at higher concentrations and stimulates proliferation at lower concentrations. This indicates the need to investigate the mechanisms of action of both Chlorella vulgaris algae extract and IAA in cancer and bacterial cells. Full article

Fusarium spp. cause devastating crop diseases and produce carcinogenic mycotoxins such as fumonisins, threatening global food safety and human health. In this study, Trichoderma longibrachiatum A25011, isolated from apples in Aksu, Xinjiang, exhibited significant antagonistic activity with mycelial growth inhibition rates of 54.52% against F. verticillioides 48.62% against F. proliferatum, and 58.22% against F. oxysporum in confrontation assays. Enzyme activity detection revealed high chitinase (583.21 U/mg protein) and moderate cellulase (43.92 U/mg protein) production, which may have the capacity to degrade fungal cell walls. High-Performance Liquid Chromatography–Mass Spectrometry (HPLC-MS/MS) analyses enabled the quantification of fungal hormones including gibberellin A3 (GA3, 2.44 mg/L), cytokinins (cis-zeatin riboside (CZR): 0.69 mg/L; trans-zeatin riboside (TZR): 0.004 mg/L; kinetin: 0.006 mg/L), and auxins (indole-3-acetic acid (IAA): 0.35 mg/L; abscisic acid: 0.06 mg/L). Application of a T. longibrachiatum A25011 spore suspension around the roots of peanut plants enhanced growth by 13.20% (height), 5.65% (stem and leaf biomass), and 39.13% (root biomass). Notably, A25011 reduced F. proliferatum-derived fumonisin accumulation in rice-based cultures by 93.58% (6 d) and 99.35% (10 d), suggesting biosynthetic suppression. The results demonstrated that T. longibrachiatum strain A25011 exhibited excellent biocontrol capability against Fusarium spp., proving its dual role in simultaneously suppressing fungal growth and fumonisin accumulation while promoting plant growth. T. longibrachiatum A25011 could be applied as a multifunctional biocontrol agent in sustainable agriculture in the future. Full article

Background: Gut barrier dysfunction and altered gut microbial metabolism are emerging signatures of chronic gut disorders. Considering growing interest in combining structurally and mechanistically distinct bioactives, we investigated the individual and combined effects of serum-derived bovine immunoglobulin (SBI) and N-acetylglucosamine (NAG) on the gut microbiome and barrier integrity. Methods: The validated ex vivo SIFR^® (Systemic Intestinal Fermentation Research) technology, using microbiota from healthy adults (n = 6), was combined with a co-culture of epithelial/immune (Caco-2/THP-1) cells. Results: While SBI and NAG already significantly improved gut barrier integrity (TEER, transepithelial electrical resistance, +21% and +29%, respectively), the strongest effect was observed for SBI_NAG (+36%). This potent combined effect related to the observation that SBI and NAG each induced distinct, complementary shifts in microbial composition and metabolite output. SBI most selectively increased propionate (~Bacteroidota families) and health-associated indole derivatives (e.g., indole-3-propionic acid), while NAG most specifically boosted acetate and butyrate (~Bifidobacteriaceae, Ruminococcaceae, and Lachnospiraceae). The combination of SBI_NAG displayed effects of the individual ingredients, thus, for instance, enhancing all three short-chain fatty acids (SCFA) and elevating microbial diversity (CMS, community modulation score). Conclusions: Overall, SBI and NAG exert complementary, metabolically balanced effects on the gut microbiota, supporting combined use, particularly in individuals with gut barrier impairment or dysbiosis linked to lifestyle or early-stage gastrointestinal disorders. Full article

Chronic kidney disease (CKD), which affects over 850 million individuals globally, is increasingly regarded as a systemic condition in which the gut microbiota represents a key pathogenic node. This review provides an integrated overview of mechanistic, translational and clinical data implicating the gut–kidney axis in CKD. The CKD-associated microbiota displays a characteristic dysbiosis, marked by depletion of short-chain fatty acid–producing commensals, overgrowth of proteolytic and urease-expressing taxa and disruption of epithelial barrier integrity. These disturbances favor the generation and systemic accumulation of gut-derived uremic toxins, most notably indoxyl sulfate, p-cresyl sulfate, indole-3-acetic acid and trimethylamine-N-oxide, which promote endothelial dysfunction, vascular calcification, fibrosis and chronic inflammation, thereby hastening renal function loss and heightening cardiovascular risk. Microbiome-directed interventions, including dietary modification, prebiotics, probiotics, synbiotics, intestinal dialysis, fecal microbiota transplantation, gut-acting sorbents and nephroprotective phytochemicals, are summarized with emphasis on their effects on uremic toxin burden and clinical surrogates. System-level implications of the gut–kidney axis for cardiovascular disease, immunosenescence and sarcopenia are discussed, together with future priorities for integrating multi-omics profiling and precision microbiome-based strategies into nephrology practice. Full article

Avicennia germinans, a representative of the marine coastal mangrove ecosystem, vital in the Colombian Caribbean, harbors a unique microbial diversity that could contain microorganisms with the potential to promote plant growth of agricultural species such as maize. The objective of this research was to evaluate A. germinans endophytes at different sampling sites and in diverse plant organs in order to identify the growth-promoting role of the most sodium chloride-tolerant endophyte found. These were then inoculated in maize seeds under drought stress conditions simulated by polyethylene glycol (PEG) in vitro. To this end, samples of adult A. germinans plants were collected from four mangrove ecosystems in the Colombian Caribbean. Several isolates were able to tolerate up to 15% NaCl (w/v), produce indole-3-acetic acid (IAA), show proteolytic activity, and inhibit phytopathogenic fungi. The best-performing strain, C1T-KM1901-B, was genomically identified as Bacillus paralicheniformis and evaluated as a bioinoculant in maize seeds under PEG-induced drought stress. Inoculation with B. paralicheniformis significantly increased germination potential and germination index of drought-resistant seeds compared to non-inoculated controls under severe drought stress conditions (40% PEG). In addition, inoculated seedlings exhibited significantly higher roots and shoot fresh and dry biomass at moderate to severe drought stress levels (15% and 20% PEG). These results are position B. paralicheniformis C1T-KM1901-B, isolated from Avicennia germinans, as a promising bioinoculant to enhance maize establishment under drought conditions. Full article

Waterlogging is a major abiotic stress that restricts plant growth, productivity, and survival by disrupting root aeration and altering hormonal homeostasis. To elucidate the physiological and molecular responses associated with flooding tolerance in Liriodendron hybrids (Liriodendron chinense × Liriodendron tulipifera), this study investigated its morphological, physiological, and transcriptomic changes under 0, 1, 3, and 6 days of waterlogging. Roots exhibited rapid decay, while leaves showed delayed chlorosis and reduced chlorophyll content. Changes in antioxidant enzyme activities reflected enhanced antioxidant capacity, with superoxide dismutase (SOD) activity decreasing and peroxidase (POD) and catalase (CAT) activities increasing. Hormone measurements indicated organ-specific patterns, including abscisic acid (ABA) accumulation in leaves and decreased indole-3-acetic acid (IAA) and gibberellin (GA) levels in both roots and leaves. Transcriptome profiling revealed extensive transcriptional adjustments in hormone biosynthesis, signaling, and stress-responsive pathways, including divergent regulation of ABA-associated genes in leaves and roots and broad downregulation of auxin- and gibberellin-related genes. Key ABA biosynthetic genes (NCED1, ABA2) and signaling components (PYL4, PP2C, ABF) were upregulated in leaves but downregulated in roots, whereas auxin (YUC6) and gibberellin (GA20ox) genes were generally suppressed. These coordinated physiological and molecular responses suggest organ-differentiated adaptation to waterlogging in Liriodendron hybrids, highlighting candidate pathways and genes for further investigation and providing insights for improving flooding tolerance in woody species. Full article

The auxin/indole-3-acetic acid (Aux/IAA) gene family encodes central regulators of plant development and stress adaptation. Eggplant (Solanum melongena), an economically important vegetable crop, is highly susceptible to abiotic stresses, yet its Aux/IAA family remains uncharacterized. This study aimed to systematically characterize the Aux/IAA gene family in eggplant and to explore its potential roles in development and abiotic stress responses using a genome-wide approach. Here, 35 SmIAA genes were identified through comprehensive bioinformatic analyses, including phylogenetic classification, synteny analysis, protein–protein interaction prediction, and qRT-PCR validation. Phylogenetic analysis classified these genes into Clades A and B, encompassing nine subgroups, with subgroup B4 showing lineage-specific expansion and encoding non-canonical Aux/IAA proteins. Expression profiling revealed that SmIAA18 and SmIAA33 were strongly responsive to salt stress, whereas SmIAA1/2/8 were preferentially induced by drought stress. Furthermore, SmIAA8 and SmIAA33 exhibited contrasting responses to IAA treatment, characterized by delayed induction and rapid repression, respectively. This study presents the first genome-wide analysis of the Aux/IAA family in eggplant, elucidating its roles in development and stress adaptation, and provides valuable genetic resources for the molecular breeding of stress-tolerant varieties. Full article

Aims: The plant and soil microbiome serve as a reservoir of beneficial endophytic bacteria, including plant-growth-promoting (PGP) Bacillus subtilis, which enhances nutrient acquisition and protects plants against environmental stresses. We isolated novel bacteria from cultivated peanut plants selected from agricultural fields that survived a season of water scarcity and high temperatures. Experiments were conducted to determine whether plant survival was partially attributable to the presence of beneficial microbes that could be harnessed for future biotechnology applications. Methods and Results: Seven bacterial isolates of Bacillus spp. were identified through 16S rRNA sequencing, revealing close affiliations to B. subtilis, B. safensis, and B. velezensis. Growth curve analysis and colony morphology characterization revealed distinct growth patterns across different media types, while phytohormone production assays demonstrated variable indole-3-acetic acid (IAA) synthesis among isolates. When applied as seed biopriming agents to two hybrid peanut varieties, bacterial inoculation significantly enhanced root surface area and root tip development, with B. subtilis-TAM84A showing the most pronounced effects on ‘Schubert’ roots. In addition, vegetative growth assessments indicated increased branch numbers and plant height, particularly with treatments with B. velezensis strains TAM6B and TAM61A, and a consortium of all isolates. Under drought conditions, inoculated plants exhibited delayed wilting and improved recovery after rehydration, indicating enhanced drought resilience. Conclusions: Several local Bacillus strains recovered from drought-tolerant peanut plants showed improved growth and drought tolerance in greenhouse-grown peanut plants. Ongoing field studies aim to evaluate the potential of regionally adapted microbial populations as soil amendments during planting. Impact Statement: This study demonstrates that local strains of Bacillus isolated from drought-resistant peanut plants possess significant potential as bioinoculants to improve growth and drought tolerance in potted peanut plants. This work provides a foundation for utilizing regionally adapted microbial populations to address agricultural challenges related to water scarcity. Full article

Salinity is among the main abiotic constraints limiting crop productivity worldwide. Salt tolerance can be improved by introducing adaptive traits from wild species and enhancing pre-existing salt-adaptive mechanisms through priming. This study evaluated the beneficial effect of salicylic acid (SA, 1.25 mM) and calcium chloride (CaCl₂, 5 mM) seed priming on plant growth under salinity in the domestic barley Hordeum vulgare (Hv) and the wild, salt-adapted Hordeum maritimum (Hm). Primed plants were grown under control, 100 and 200 mM sodium chloride (NaCl) for two weeks. Growth and hormone profiling were performed. Hv showed higher growth inhibition than Hm but was more responsive to stress alleviation by priming, particularly with SA, which increased biomass by up to 47% at 200 mM NaCl. The contrasting responses of both species reflected distinct hormonal strategies. The intrinsic salt tolerance of Hm appears linked to high constitutive levels of stress- and growth-related hormones. In Hv, growth recovery under salinity following priming was associated with hormonal reprogramming, involving reduced abscisic acid (ABA) accumulation and enhanced levels of growth-promoting hormones (indole-3-acetic acid (IAA), trans-zeatin (tZ), and isopentenyl adenine (iP)), especially in roots. Hormonal changes mediated by priming are analyzed in relation to adaptive growth responses and species’ ecological origins. Full article

The increasing environmental challenges facing modern agriculture necessitate development of sustainable, eco-friendly alternatives to chemical inputs. This study aimed to isolate and characterize rhizophilic bacterial strains from the rhizosphere of the maize hybrid Turan 480 SV (Zea mays L.), with a focus on their plant growth-promoting and biocontrol traits. A total of 23 bacterial isolates were obtained, including 15 Gram-negative and 8 Gram-positive strains. Among these, three strains—CR14, CR18 and CR22—were selected for detailed analysis. All three demonstrated significant indole-3-acetic acid (IAA) production, phosphate and zinc solubilization, nitrogen fixation and antifungal activity. CR14 synthesized 56.01 mg L⁻¹ of IAA and demonstrated the highest zinc solubilization, while CR18 exhibited superior phosphate solubilization and protease activity. CR22 produced the highest IAA (61.46 mg L⁻¹) and demonstrated strong cellulase and amylase activity. In antagonism tests, CR14 suppressed Alternaria alternata with an 80 mm inhibition zone, while CR18 and CR22 effectively inhibited both A. alternata and Fusarium graminearum. Phylogenetic analysis based on 16S rRNA sequencing identified CR18 as Serratia quinivorans, CR14 as Pantoea agglomerans and CR22 as Pantoea sp. The functional diversity of rhizobacteria holds promise as bioinoculants for enhancing maize growth and protecting against soil-borne pathogens in sustainable agriculture. Full article

Meloidogyne incognita is one of the most detrimental root-knot nematodes (RKNs) globally. The restricted application of chemical nematicides has resulted in an increasing inclination towards environment-friendly alternatives. In this study, a strain of Pseudomonas aeruginosa XR2-39, which was isolated from compost fermentation of edible fungus residue, exhibited effective biocontrol activity against M. incognita. In vitro experiments employing the fermentation filtrate of strain XR2-39 achieved high nematicidal efficacy of second-stage juveniles (J2s), resulting in corrected mortality rates of 97.12% and 100% after 24 h and 48 h, respectively. The fermentation filtrate also demonstrated a high relative hatching inhibition for egg masses (97.87%) and free eggs (100%). In addition, strain XR2-39 exhibited strong capabilities in indole-3-acetic acid (IAA) production (with a yield of 33.01 mg/L), siderophore production (with a yield of 71.45% unit), and phosphate solubilization (with a dissolved amount of 831.15 mg/L). Pot experiments indicated that the incubation of tomato roots with 20% fermentation broth led to an increase in fresh shoot weight, root weight, shoot length, root length, and stem diameter by 448.57%, 136.36%, 179.29%, 49.39%, and 57.14%, respectively, when compared to the water control. Moreover, the inoculation with 20% fermentation broth significantly decreased tomato root galls, resulting in a gall index of 37.00, which was significantly lower than that of the water-control treatment (77.50). Furthermore, the active compound in the fermentation filtrate remained stable within the pH range of 7.0 to 11.0, maintaining a corrected mortality rate of over 89.0%. It also demonstrated thermostability, as the boiled fermentation filtrate (treated at 120 °C for 2 h) showed a high corrected mortality rate against J2s. Additionally, the active substance displayed strong UV tolerance and storage stability. These characteristics of active compounds make strain XR2-39 a promising biocontrol agent for M.incognita. Full article