Search Results (1,685)

Spent mushroom substrate (SMS) is a major agricultural byproduct whose complex lignocellulosic matrix hinders direct reuse and poses environmental risks when stockpiled. This study evaluated whether pretreatment with plant growth-promoting rhizobacteria (PGPR) could enhance SMS as a soil amendment for blueberry cultivation. Two PGPR-treated SMS formulations, along with raw SMS and a blank control, were applied to blueberry seedlings in a 10-month greenhouse experiment. Plant height, rhizosphere soil nutrients, enzyme activities, lignocellulose fractions, and the microbial communities were monitored over three growth phases and four sampling points. PGPR-treated SMS significantly increased blueberry height gain during the fast-growing phase (June–September) and sustained elevated levels of organic carbon, nitrogen, phosphorus, and potassium throughout the experiment. Activities of cellulase, xylanase, laccase, peroxidase, protease, and lipase were markedly enhanced, accompanied by reduced lignin and cellulose contents and persistently high glucose availability. The amendments reshaped bacterial and fungal communities, enriching Bacillota, Acidobacteriota, Acidibacter, and Hyphomicrobium, and increasing alpha diversity, with clear structural separation from controls in principal coordinate analysis. Correlation and principal component analyses linked improved plant growth to nutrient availability, enzyme stimulation, and specific microbial taxa. These findings indicate that PGPR-treated SMS acts as a multifunctional amendment that promotes lignocellulose degradation, sustains soil fertility, and restructures the rhizosphere microbiome, offering a sustainable recycling strategy for horticultural production. Full article

The continuous growth of the global population and the need to ensure food security require the development of sustainable agricultural technologies capable of maintaining crop productivity while reducing environmental impact. Nitrogen-fixing bacteria belonging to the genera Azotobacter and Azospirillum have attracted increasing interest due to their ability to improve plant nutrition and stimulate physiological processes associated with growth and productivity. The aim of the present study was to evaluate the effect of the commercial biostimulant Azotofertil, based on Azotobacter chroococcum and Azospirillum lipoferum, on the agrophysiological response of tomato and pepper plants, in comparison with conventional nitrogen and phosphorus fertilization. A field experiment was conducted using a randomized block design with three fertilization treatments and three biological replicates for each crop species. Soil pH, cultivable Azotobacter spp. populations, plant height, photosynthetic pigment content, vitamin C content, and total yield were evaluated. Data were analyzed using one-way analysis of variance (ANOVA), followed by Duncan’s multiple range test (p < 0.05) and Pearson correlation analysis. The application of Azotofertil significantly increased the abundance of cultivable Azotobacter spp., photosynthetic pigment content, and vitamin C content, while no statistically significant differences were observed for soil pH or plant height. The most pronounced effect was observed for photosynthetic pigment content, which increased by 26% in tomato and by 21% in pepper compared to the control. Full article

Background: Accurate assessment of microelement and toxic element content in animal diets is essential for diet formulation, quality control, and exposure assessment; however, predictive additive models may not fully account for variability arising from raw materials and processing factors. Methods: This study evaluated the composition of microelements and toxic elements in the four diets enriched with 4% beetroot cultivars Boldor and Wodan, either without (level 1) or with (level 3) foliar application of the selenium–based plant growth stimulator. Predicted values (calculated using an additive model P = 0.96 × C _{basal diet} + 0.04 × C _{beetroot component}) were compared with experimentally measured concentrations (M). Four dietary variants Boldor 1, Boldor 3, Wodan 1 and Wodan 3 were analyzed. Elemental concentrations of Fe, Zn, Cu, Cr, Ni, Se, Pb, As, Cd, and Sb were determined using ICP-MS. Results: Substantial discrepancies between predicted (P) and measured (M) values were observed. The largest deviations occurred for Cr, Fe, and Sb. Cr and Sb were generally underestimated by the model, whereas Fe was consistently overestimated. Selenium (Se) showed moderate variability, while Cu, Zn, and Ni exhibited close agreement between predicted and measured values. The largest measured cultivar-related differences were observed for As (2.87-fold), Cd (2.78-fold), Pb (2.47-fold), Cr (2.37-fold), Fe (1.73-fold), Sb (1.57-fold), Cu (1.13-fold), and Zn (1.05-fold), all of which occurred at higher concentrations in Wodan than in Boldor. No statistically significant effect of the selenium–based plant growth stimulator was observed. Conclusions: Overall, the results demonstrate that additive models have limited accuracy in predicting trace element composition in complex diets, particularly for elements potentially affected by raw-material variability, sampling heterogeneity, and analytical uncertainty. The contribution of the dietary 4% beetroot component played a key role in shaping element distribution, particularly for elements with high component-to-basal diet ratios. These findings highlight the importance of proper mixing, prevention of segregation in powdered diets, and strict control of raw material quality. Full article

Brazilian cattle production relies predominantly on pasture systems, many of which are degraded by nutrient depletion, particularly nitrogen deficiency. Plant growth-promoting bacteria (PGPB) offer a sustainable strategy to improve pasture productivity, but their effects are often host-specific and remain poorly explored in Paspalum. This study evaluated the effect of inoculation with Azospirillum brasilense strains CNPSo 2083 (=Ab-V5) and CNPSo 2084 (=Ab-V6) and Pseudomonas fluorescens strain CNPSo 2719 (=CCTB 03), applied by seed inoculation or leaf spray, on the root morphology and shoot growth of four Paspalum accessions under controlled axenic greenhouse conditions, evaluated in an early growth stage at 35 days after emergence. Genotype-specific responses were the central finding of this study: Paspalum malacophyllum BGP-293 showed negligible responses to inoculation, whereas BGP-486—of the same species—increased root dry weight by up to 43% and root tissue density by up to 30% in all inoculated treatments. In Paspalum regnellii BGP-112, seed inoculation produced stronger root responses than foliar spray, increasing root dry weight by up to 38% and root area by up to 40%. In Paspalum rojasii BGP-149, inoculation induced root architectural remodeling without increasing root biomass—root area increased by up to 92% and total root length by up to 97%, relative to the control—indicating an efficient root-foraging strategy. P. fluorescens favored root-foraging traits and tissue density, whereas A. brasilense preferentially stimulated root-hair elongation. These accession-level contrasts, rather than a single generalizable trend, are the main contribution of this work: they support tailored, genotype-specific PGPB strategies for sustainable tropical pastures. Full article

Agrochemicals are used worldwide in food production, but their use varies between countries due to the damage observed to nature and human health. Allelopathy is the primary pathway of chemical communication in plants, interfering with biome development through stimulation and/or inhibition mechanisms. Therefore, this study aimed to assess the biological activities of the ethanol extract (EE) and fractions of S. fluminensis leaves on monocotyledonous and eudicotyledonous models. The EE was obtained by percolation with ethanol, and the hexane (HEXF), dichloromethane (DCMF), ethyl acetate (EAF), and hydroethanol (HEF) fractions were obtained by liquid–liquid partition. The phytochemical characterization was performed by ¹H nuclear magnetic resonance (NMR). The allelopathic activity was evaluated on Allium cepa (onion) and Lactuca sativa (lettuce) seeds. The cytotoxic, genotoxic, and antigenotoxic effects on A. cepa meristematic cells were analyzed in vitro. Aliphatic compounds, saponins, and flavonoids derived from quercetin and kaempferol were characterized in the samples. All samples decreased the vigor, germination rate, and germination speed index (GSI) of A. cepa seeds. In contrast, they did not alter the vigor and viability of L. sativa seeds, but decreased the GSI, except for HEF. The samples inhibited the epicotyl and root growth of A. cepa and L. sativa, except HEXF, which stimulated the growth of epicotyls (750 µg/mL) and roots (750 and 1000 µg/mL). The cytotoxic assays showed that the EE and HEXF had cytotoxic action at low concentrations, and no sample showed a genotoxic effect. The following samples exhibited an antigenotoxic effect after pretreatment with atrazine (ATZ): EE (125 and 750 µg/mL), HEXF (750 and 1000 µg/mL), DCMF (125, 250, and 1000 µg/mL), EAF (at all tested concentrations), and HEF (125, 250, and 750 µg/mL). Furthermore, the EAF at 125 and 500 µg/mL and HEF at 125 µg/mL demonstrated the potential to reverse genetic damage induced by glyphosate (GLY). Full article

Symbiotic nitrogen fixation (SNF) in forage legumes is a key biological process that provides nitrogen inputs and enhances soil fertility in agroecosystems. Enhancing SNF efficiency helps reduce dependence on synthetic nitrogen fertilizers and improve nitrogen use efficiency. Humic substances (HS) have been reported to stimulate root development and nutrient acquisition in different crop species. However, their effect on root nodulation and SNF in forage legumes remains poorly understood. This study investigated the effects of a humic acid-based soil amendment (liquid Humalite) on root growth, nodulation, SNF, and plant nitrogen acquisition in red clover. Red clover seedlings were grown in a modified Leonard jar system placed under controlled environmental conditions and treated with 0.1, 0.2, 0.4, and 0.8% (v/v) liquid Humalite. Plant biomass, root morphological traits, nodulation parameters, SNF, and shoot nitrogen accumulation were assessed after 6 weeks. SNF was quantified using the ¹⁵N-isotope dilution method. Application of liquid Humalite significantly affected plant growth and SNF responses in red clover. The 0.2% liquid Humalite treatment significantly increased root and total plant biomass by 35% compared to the untreated control. Total root length, surface area, and volume increased by 20–25% at 0.2% liquid Humalite. Nodule number, nodule dry weight, shoot nitrogen concentration, and shoot C:N ratio did not differ among treatments. However, the percent nitrogen derived from the atmosphere (%Ndfa) was significantly higher under the 0.2% liquid Humalite treatment (47%) as compared to the untreated control (28%). Under the 0.2% liquid Humalite, total fixed and accumulated shoot nitrogen increased by 134% and 37%, respectively, compared to the control. Overall, these findings indicate that humic substances may enhance SNF and nitrogen accumulation in red clover, highlighting their potential as a management strategy to improve forage productivity. Full article

Orchid seeds are dust-like and lack endosperm, which limits their capacity to support germination using endogenous nutrient reserves. Successful germination therefore depends on the establishment of a compatible symbiotic association with germination-promoting orchid mycorrhizal fungi (OMF). In plant-root symbioses, host-derived small molecules, such as strigolactones and flavonoids, function as early chemical signals that recruit microbial partners and stimulate their growth. However, the chemical constituents that may facilitate fungal recognition, growth, or colonization during orchid seed germination remain poorly understood. In this report, we combined metabolomics, UPLC-Q-TOF-MS/MS, molecular networking, phytochemical isolation, and bioactivity assays to characterize bioactive metabolites from the seeds of the medicinal orchid Cremastra appendiculata. Metabolomic profiling revealed abundant primary metabolites, including lipids, amino acids, organic acids, saccharides, and nucleosides. And then, nineteen secondary metabolites were isolated and identified, including two new structures. Functional assays showed that selected organic acids, saccharides, and lignanamides promoted the growth of Coprinellus disseminatus, a fungus required for seed germination, whereas lignanamides inhibited the plant pathogen Fusarium oxysporum. These findings provide the first systematic chemical and functional characterization of metabolites from C. appendiculata seeds and offer new insight into the molecular basis of symbiosis between orchids and fungi. Full article

Eggplant (Solanum melongena L.), the world’s fifth most important vegetable crop, is highly sensitive to waterlogging (WL), which limits its productivity under climate-driven flooding events. This study evaluated whether humic acid (HA) and fulvic acid (FA) alleviate WL-induced stress by improving nutrient acquisition and antioxidant defense. Eggplant seedlings were subjected to WL stress for 10 days with and without bio-stimulant treatments, under controlled conditions using a simple, completely randomized design. Waterlogging deteriorated soil properties, reducing pH from 7.7 to 5.4, organic matter by ~75%, soil nutrients 73%, resulting in a decline in plant growth (61%), nutrients (23–74%), chlorophyll concentrations (25–45%), and increased oxidative stress indicators (33–314%). Both HA and FA significantly mitigated these stress effects, restoring plant growth by 11–43%, increasing chlorophyll by ~42%, and enhancing nutrients by 10–17-fold. However, HA and FA differentially modulated stress responses. HA reduced H₂O₂ and MDA by 40–75% and normalized antioxidant enzyme activities, indicating redox homeostasis, while FA maintained relatively higher H₂O₂ levels (133.7 mmol kg⁻¹) while improving growth and chlorophyll (~32–67%), suggesting a stress priming rather than stress suppression mechanism. Overall, HA conferred WL tolerance by limiting oxidative damage, whereas FA promoted growth through reactive oxygen species signaling, supporting the potential of humic substances as sustainable bio-stimulants for climate-resilient crop production. Full article

A reasonable branch bending angle is essential for optimizing canopy structure and regulating metabolic distribution in fruit trees. ‘Jinyefoxilan’ is a new olive variety bred by crossing ‘Frantoio’ and Olea cuspidata Wall., characterized by rapid growth and high oil concentration. This study evaluated the physiological and metabolic responses of ‘Jinyefoxilan’ to natural growth (CK), 60°, 90°, and 110° bending. Parameters including leaf morphology, photosynthetic pigments, endogenous hormones, mineral distribution, and fruit quality were analyzed. The results demonstrated that the 60° treatment stimulated leaf gibberellin synthesis. The 90° treatment facilitated the synergistic enrichment of nitrogen and potassium in leaves, resulting in the highest fruit oil concentration, although the yield per plant was the lowest among all treatments. Conversely, 110° bending significantly altered the endogenous hormonal balance, with indole-3-acetic acid concentration reaching 13.3 times that of the CK. This treatment achieved the numerically highest fruit set rate and yield per plant, accompanied by significant accumulations of calcium, magnesium, and phosphorus. However, the 110° angle also induced severe N and K deficits, resulting in the lowest fruit moisture and oil concentration. In conclusion, 90° branch bending represents the optimal strategy for enhancing intrinsic fruit quality and oil accumulation. Although 110° bending maximizes yield, it necessitates supplemental potassium fertilization during fruit development to mitigate metabolic limitations. These findings provide a theoretical and practical basis for canopy management and cultivation of ‘Jinyefoxilan’ olives. Full article

Most Citrus spp. trees in China are cultivated in acidic soils with low soil organic matter and high Al³⁺. The mechanisms of humic acid (HA) to alleviate Al³⁺ stress in plants remain unclear. ‘Sour pummelo’ (Citrus grandis (L.) Osbeck) seedlings were exposed to 0.5 (HA0.5), 0.1 (HA0.1), or 0 (HA0) mM sodium humate and 1.2 (Al1.2) or 0 (Al0) mM AlCl₃·6H₂O for 128 days. Thereafter, the research examined biomass; Al and mineral nutrients; leaf photosynthetic performance; and leaf and root nonstructural carbohydrates, reactive oxygen species metabolism, and related physiological parameters. Al1.2 significantly reduced whole plant dry weight (DW), root DW, leaf CO₂ assimilation (A_CO2), and chlorophyll a + b concentration by 61%, 45%, 61%, and 35%, respectively, at HA0, but only 48%, 17%, 44%, and 11%, respectively, at HA0.5. Further analysis suggested that the addition of HA endowed Citrus with Al resilience by the following several aspects: (a) lessened tissue (leaf, stem, and root) concentrations of Al and enhanced capacity to maintain macronutrient (S, K, Mg, Ca, N, and P) homeostasis at Al1.2; (b) improved capacity to combat oxidative stress at Al1.2; and (c) enhanced A_CO2 and growth at Al1.2. Further analysis indicated that HA-mediated alleviation of growth decline caused by Al1.2 involved (a) reduced ability to absorb Al and less root-to-shoot Al transport and (b) increased ability to maintain macronutrient homeostasis and to combat oxidative stress; and that HA-mediated alleviation of leaf chlorophyll and A_CO2 decline and photosynthetic electron transport chain impairment involved less leaf Al concentration and improved leaf macronutrient homeostasis. To conclude, the addition of HA lowered roots’ ability to absorb Al and tissue Al concentration and subsequently mitigated Al-toxic impairment to root growth and function, thereby enhancing the ability of plants to maintain macronutrient homeostasis, and hence alleviating Al1.2-stimulated oxidative damage and inhibition of A_CO2 and growth. Full article

Water hyacinth (Eichhornia crassipes, WH) is a highly invasive aquatic plant. Although its surplus biomass has been proposed as an agricultural amendment, uncertainty remains regarding its safe use. Based on this knowledge gap, two working hypotheses were addressed: (i) WH application would enhance soil physicochemical and enzymatic attributes, particularly under water stress, and (ii) WH application would stimulate plant growth through nutrient release. To verify this, two WH amendment rates (2.5% and 5% w/w) were evaluated under normal (45%) and severe (22.5%) WHC using tomato (Solanum lycopersicum L.) as a bioindicator. WH incorporation significantly altered soil conditions, inducing progressive acidification and increasing electrical conductivity (EC), particularly at the 5% rate under well-watered conditions, where EC values reached approximately 3000 µS/cm. Although WH amendments increased soil relative humidity owing to the hydrophilic nature of the biomass, these moisture-driven benefits were transient. Acid phosphatase activity increased markedly by day 60 in WH-amended soils, especially at 45% WHC, indicating enhanced microbial activity and phosphorus mineralization associated with organic matter decomposition. Plant responses were strongly driven by water availability, with severe water restrictions consistently limiting germination and growth and potentiating osmoprotectant retention. From day 60 onward, germination and biomass declined markedly in the 5% WH treatment, likely due to the accumulation of salt and osmotic stress arising from the decomposition of biomass. Surviving seedlings in WH-amended soils exhibited increased shoot biomass relative to their roots, suggesting stress-related biomass reallocation. Overall, the results indicate that the direct application of untreated WH biomass at moderate to high rates may generate short-term benefits but may impair long-term plant establishment. Lower application rates (≤2.5% w/w) may offer limited early stage benefits, whereas higher rates pose risks under prolonged exposure, highlighting the importance of dose, water regime, and amendment processing when considering WH valorization for agricultural use. This valorization approach may contribute to incentivizing control of this invasive species while promoting plant waste valorization within circular economy goals. Full article

Hydroponic production of vegetables is beneficial for plant yield and quality, especially when utilizing growth stimulators. To evaluate the effect of Se/Si nanoparticle application, two contrasting lettuce types of relatively low (Iceberg) and high (Romaine) nutritional density were foliar-treated with nanoparticles of Se (25 mg L⁻¹) and Si (14 mg L⁻¹), singly or jointly. Only single nano-Se/Si supply showed a beneficial effect on lettuce yield, photosynthetic pigments, and antioxidant parameters. Compared to Romaine, Iceberg displayed a lower yield increase under nano-Se/Si supply, despite the higher photosynthetic pigment rise, while Romaine lettuce was characterized by a significantly higher augmentation of ascorbic acid, polyphenols, and total antioxidant activity (AOA). Nano-Se/Si halved the chlorophyll a/b ratio in Iceberg, with no effect on Romaine lettuce. Iceberg showed more evident mineral profile changes under all Se/Si treatments, with a significant Mn increase and Fe decrease. In both lettuce types, single nano-Se supply reduced Cu accumulation by more than twice, while joint Se/Si treatment significantly diminished both Cu and Zn. Nano-Si supplementation had contrasting effects on Cu, Zn, and Mn accumulation, increasing the assimilation capacity of minerals in Iceberg and decreasing Cu and Mn levels in Romaine, with no significant effect on Zn. Under single Se supply, both lettuce types provided 920–1030 µg Se kg⁻¹ d.w., compared to lower values (611–720 µg kg⁻¹ d.w.) associated with joint Se/Si treatment. The results of this research confirm the existence of significant genetic peculiarities in plant adaptation connected with photosynthetic pigment accumulation and mineral profile changes in the Iceberg genotype and with antioxidant parameters in Romaine lettuce. Full article

Saline–alkali stress severely restricts cucumber (Cucumis sativus L.) growth by disrupting ion balance, water status, photosynthesis, and redox homeostasis. Here, we examined the effects of exogenous selenium (Se) on cucumber seedlings exposed to NaHCO₃ stress. Se supplementation improved plant growth and root activity and partly restored photosynthetic performance by maintaining chlorophyll content, gas exchange, and chlorophyll fluorescence. Se reduced oxidative injury through lower ROS and MDA levels and by enhancing antioxidant enzyme activities together with the AsA–GSH cycle. In parallel, Se moderated ion toxicity by limiting Na⁺ accumulation, increasing K⁺, Ca²⁺, and Mg²⁺ uptake, and stimulating H⁺-ATPase and H⁺-PPase activities. Enhanced TCA cycle activity and organic acid accumulation suggested improved energy metabolism and ionic regulation. Se also promoted osmotic adjustment via soluble sugars and proline, and upregulated aquaporin genes (PIP1;2 and PIP2;4) to sustain water transport. Moreover, Se increased salicylic acid levels by upregulating CsPAL and CsICS, pointing to a role of SA signaling in Se-induced tolerance. Full article

Perfluorotetradecanoic acid (PFTeDA), a long-chain per- and polyfluoroalkyl substance (PFAS), is highly persistent and bioaccumulative, yet its effects on soil bacterial communities remain poorly understood. This study evaluated the impact of PFTeDA on the taxonomic composition, diversity, and functional potential of soil bacteria, and assessed whether biostimulants (Shigeki and Aminoprim) could mitigate these effects and improve the growth of Amaranthus cruentus. A pot experiment was conducted using Eutric Cambisols soil (pH 4.62), and bacterial communities were analyzed by 16S rRNA gene sequencing. PFTeDA significantly altered bacterial community composition, reducing the abundance of Actinomycetota, Chloroflexota, and Gemmatimonadota, while also changing alpha and beta diversity and predicted functional profiles. Biostimulant application partially alleviated these effects by promoting recovery of the soil bacterial communities and bacteria associated with nitrogen cycling and organic matter degradation, indicating partial restoration of soil ecosystem functions. PFTeDA reduced aboveground biomass but increased root biomass of A. cruentus, without affecting leaf greenness (SPAD). Both biostimulants enhanced plant growth and SPAD values, with Aminoprim exerting a stronger effect on shoot biomass and Shigeki stimulating root development. This study demonstrates that PFTeDA affects not only the taxonomic composition of the soil bacterial communities but, above all, its stability and predicted functional potential, representing a key mechanism underlying its impact on the soil–plant system. It also highlights that biostimulation may serve as an effective tool supporting the potential improvement in soils contaminated with persistent organic compounds. Full article

The early post-weaning period in piglets is characterized by physiological and environmental stress that can impair intestinal function and growth performance. Plant-derived feed additives have gained interest as a nutritional strategy to support gut integrity and productivity. Extracts from Cynara scolymus stimulate bile secretion and exhibit antioxidant properties, whereas inulin may promote beneficial microbial populations and intestinal functionality through prebiotic activity. This study evaluated the biological activity of a feed additive containing Cynara scolymus extract and inulin on intestinal functional indicators and productive performance of post-weaned piglets under intensive production conditions. Four hundred and eight piglets were randomly assigned to two groups: a control group (CON) that was fed a basal diet, and a treatment group (CSI) that was supplemented with the additive (5% Cynara scolymus extract and 14% inulin) at 300 g/ton of feed. Plasma cortisol and citrulline concentrations were measured during the first 15 days post-weaning. On day 16 post-weaning, intestinal parameters were evaluated, including gastrointestinal pH; enterobacteria and lactic acid bacteria counts; volatile fatty acids; bacterial adhesion to ileal mucus; disaccharidase activity; and small intestinal histomorphology. Growth performance was monitored during the 50-day nursery phase. Compared with CON piglets, CSI piglets exhibited higher plasma citrulline concentrations (72.72 ± 20.87 vs. 47.54 ± 17.05 µM; p < 0.001), indicating improved intestinal epithelial functionality. CSI supplementation also increased the villus height-to-crypt depth ratio (3.67 ± 0.75 vs. 2.68 ± 0.64; p = 0.001), suggesting enhanced intestinal epithelial integrity. Furthermore, CSI piglets showed higher average daily gain (0.53 ± 0.07 vs. 0.44 ± 0.09 kg/day; p = 0.003) and a better feed conversion ratio (1.27 ± 0.20 vs. 1.57 ± 0.57; p = 0.004). These results suggest that Cynara scolymus extract and inulin supplementation has beneficial biological effects on intestinal epithelial functionality and productive performance in post-weaning piglets under commercial conditions. Full article