Search Results (1,158)

The overuse of pesticides has raised serious food-safety and environmental concerns. Carbon dots (CDs) can act as biostimulants by enhancing photosynthesis, thereby promoting plant growth and stress tolerance. However, their roles in plant pesticide detoxification remain unclear. This study synthesized nitrogen-doped carbon dots (N-CDs) with strong blue fluorescence, excellent biocompatibility, and no cytotoxicity observed in HEK 293T cells. The N-CDs were synthesized from 1.025 g citric acid and 0.379 g urea, producing particles with a size of around 2.42 nm and abundant hydrophilic groups. When applied to tomato plants, N-CDs (especially at 150 mg·L⁻¹) significantly reduced chlorothalonil (CHT) residues affecting tomato, by up to 66%. Importantly, N-CDs also improved tomato plant growth, reversing the negative effects of CHT on key parameters such as height, leaf area, and biomass. Indeed, under CHT conditions, N-CDs significantly reduced the contents of malondialdehyde, superoxide, and hydrogen peroxide. In contrast, N-CDs significantly increased the activities of superoxide dismutase, peroxidases, catalase, and ascorbate peroxidase to 117.57%, 158.53%, 162.79%, and 152.23%, respectively. Notably, N-CDs dramatically changed the glutathione pool for tomato detoxification. Overall, this study synthesized the non-cytotoxic N-CDs that not only promote tomato growth but also alleviate CHT toxicity by strengthening the tomato’s antioxidant defense system. Full article

Global concerns about resource depletion, climate change, and nutrient pollution in aquatic systems are compelling a transition towards zero-waste industries. With the skyrocketing carbon footprint of the modern fertiliser industry, sustainable options are highly sought after. Anaerobic digestion of organic waste to generate renewable biogas and fertiliser production from the residual nutrient-rich digestate are promising nutrient recovery and recycling avenues. This review explores the potential use of anaerobic digestate to develop value-added agronomic products, focusing on the quality and safety parameters pivotal to its fertiliser value. A comprehensive review of conventional and cutting-edge technologies available for digestate processing into organic/organo-mineral fertilisers has been conducted, highlighting emerging sustainable approaches. Specifically, this review unravels novel aspects of enhancing digestate quality with biostimulants such as plant growth-promoting rhizobacteria, humic substances and biochar for biofertiliser/slow-release fertiliser production. Additionally, methods and guidelines to assess and address environmental impacts by digestate application on croplands and challenges in the commercialisation of digestate-based fertilisers were analysed. This review also underscores the importance of valorising anaerobic digestate as a fertiliser in implementing a circular bioeconomy within the agroindustry. Full article

The increasing demand for sustainable agriculture has accelerated research into eco-friendly plant health management, particularly through natural substances rich in bioactive compounds. In this study, various substances, including essential oils, extracts from Aloe vera, artichoke and ornamental plants, by-products from beer and coffee processing, and selected commercial formulations including biostimulants and a plant strengthener, were evaluated for their antimicrobial properties and ability to trigger plant defenses. Notably, Agapanthus spp. exhibited strong antifungal activity against the fungus Botrytis cinerea (Bc), while thyme, tea tree, and lavender essential oils were effective against both Bc and the bacterium Pseudomonas syringae pv. tomato (Pst). Greenhouse trials on tomato plants demonstrated the protective effects of A. vera gel and ornamental plant extracts against Bc and Potato virus Y (PVY), while coffee and artichoke extracts were effective against Pst. An alginate-based formulation containing thyme oil showed enhanced in planta efficacy against the three pathogens. Gene expression analyses revealed early upregulation of PR-1 and PR-4, especially with alginate treatments and A. vera gel at 12 h post-treatment (hpt) while coffee extract triggered the strongest late response at 72 hpt. These findings highlight the potential of plant-derived substances in promoting sustainable plant disease management through both direct antimicrobial action and immune system activation. Full article

Soil amendments can enhance soil and plant health; however, limited research has addressed their effects on soil health and crop productivity in alkaline soil. This study investigated the effects of various soil amendments and biostimulants by the Haney Soil Health Test, plant sap analysis, and Cucurbita pepo cv. ‘Dunja’ yield and quality. Treatments included unamended soil (T1) and applications of Humisoil® (T2), Humisoil with biochar (T3), wood vinegar (T4), Ensoil algae^TM (T5), and Humisoil with biochar and basaltic rock dust (T6). Compared to T1, T6, T5, T2, and T3 increased yield by 107%, 87%, 86%, and 52%, respectively. Regarding total fruit number per plant, T2, T6, and T5 outperformed T1 by 42%, 37%, and 37%, respectively. Additionally, T6 decreased Na concentration by 59% in the sap of young leaves and 50% in old leaves compared to T1. Compared to T1, T2 also reduced Na concentration in the sap of old leaves by 63%. For Cl, decreases of 30%, 16%, and 24% in old leaves were observed in T2, T4, and T6 treatments, respectively. These findings highlight the potential of biostimulants and soil amendments to improve zucchini yield and quality while improving soil health in alkaline soils. Full article

The early stages of plant–microbe interaction are critical for establishing beneficial symbioses. We investigated how the endophytic fungus Fusarium solani strain FsK modulates tomato (Solanum lycopersicum) development and hormone pathways during in vitro co-cultivation. Seedlings were sampled at three early interaction stages (pre-contact, T1; initial contact, T2, 3 days post-contact, T3). Root traits and root and leaf transcripts for abscisic acid (ABA) and ethylene (ET) pathways were quantified, alongside fungal ET-biosynthesis genes. FsK altered root system architecture, increasing root area, lateral root number, root-hair length, and fresh biomass. These morphological changes coincided with tissue- and time-specific shifts. In leaves, FsK broadly affected ABA biosynthetic and homeostasis genes (ZEP1, NCED1, ABA2, AAO1, ABA-GT, BG1), indicating reduced de novo synthesis with enhanced deconjugation of stored ABA. ET biosynthesis was curtailed in leaves via down-regulation of ACC oxidase (ACO1–3), with isoform-specific changes in ACC synthase (ACS). The ET receptor ETR1 was transiently expressed early (T1–T2). FsK itself showed staged activation of fungal ET-biosynthesis genes. These results reveal coordinated fungal–plant hormone control at the transcriptional level that promotes root development during early interaction and support FsK’s potential as a biostimulant. Full article

The human gut microbiota plays a critical role in health throughout life. While fruits and vegetables are well-known sources of nutrients and prebiotics, recent studies suggest they may also contribute viable microorganisms to the gut microbiome, particularly when consumed raw. However, the impact of agricultural practices—such as the use of microbial biostimulants or exposure to salt stress—on the composition of the edible plant microbiome remains poorly understood. In this study, we performed a comprehensive metataxonomic analysis of the endophytic microbiome in the edible tissues (leaves or fruits) of lettuce (Lactuca sativa) and tomato (Solanum lycopersicum), cultivated under standard conditions with or without microbial biostimulants and salt stress. Our results show that microbial biostimulants—Priestia megaterium (PGPB) and Rhizophagus irregularis (AMF)—as well as moderate salt stress, significantly reshape the composition and diversity of endophytes in both crops. Notably, the PGPB and NaCl treatments enhanced the abundance of bacterial genera such as Pantoea, Stenotrophomonas, and Massilia, which are associated with plant health and may have probiotic potential. Salt stress also increased alpha-diversity indices and favored the presence of Firmicutes and Bacteroidota, phyla commonly linked to a healthy human gut microbiome. Agronomic inputs used in organic and conventional farming, such as microbial biostimulants or controlled salt exposure, may represent novel strategies to enhance the microbial quality of fresh produce and promote gut microbial diversity through diet. Full article

Excess sodium in soil disrupts ionic balance and limits water uptake, negatively affecting growth and stolon production in strawberry plants. This study assessed the effects of chitosan (CTS), brassinosteroids (BRs), and thidiazuron (TDZ) on stolon performance and physiological responses of strawberry cv. ‘Portola’ under saline conditions. A greenhouse experiment included seven treatments: CTS, BRs, CTS + BRs combinations, TDZ, and an untreated control. Foliar applications were used to evaluate impacts on nutrient uptake, photosynthetic pigments, oxidative stress, and stolon production. BRs alone [2.53 × 10⁻⁶ μM] significantly increased crown diameter (+43%), stolon number (+65%), stolon length (+4%), and daughter plant formation (+8%), while reducing leaf sodium by 60% and improving Mg²⁺/Na⁺ and K⁺/Na⁺ ratios. The CTS + BRs combination enhanced phenolic content and produced the heaviest first daughter plants (6.1 g). TDZ, however, resulted in weaker stolons, lower chlorophyll a content, and reduced K⁺/Na⁺ ratios, suggesting a need for dose optimization. Overall, BRs, alone or with CTS, improved salt tolerance and stolon propagation through enhanced ion regulation, photosynthesis, and antioxidant defenses. These findings advance understanding of how biostimulants modulate metal ion homeostasis, antioxidant signaling, and growth in salt-sensitive crops, offering strategies to mitigate salinity stress in strawberry cultivation. Full article

This study investigated the isolation and formulation of a bacterial conditioner as a biostimulant for Triticum durum (durum wheat) under salinity stress. An Algerian alkaline–saline soil was sampled, characterized for its physical and chemical characteristics and its culturable and total microbial community (16S rRNA gene metabarcoding). Three bacterial strains showing high 16S rRNA gene similarity to Pseudomonas putida, Bacillus proteolyticus, and Niallia nealsonii were selected for their plant growth-promoting (PGP) traits under different salinity levels, including phosphate solubilisation (194 µg mL⁻¹), hormone production (e.g., gibberellin up to 56 µg mL⁻¹), and good levels of hydrocyanic acid, ammonia, and siderophores. N. nealsonii maintained high indole production under saline conditions, while B. proteolyticus displayed enhanced indole synthesis at higher salt concentrations. Siderophore production remained stable for P. putida and N. nealsonii, whereas for B. proteolyticus a complete inhibition was registered in the presence of salt stress. The consortium density and application were tested under controlled conditions using Medicago sativa as a model plant. The effective biostimulant formulation was tested on Triticum durum under greenhouse experiments. Bacterial inoculation significantly improved plant growth in the presence of salt stress. Root length increased by 91% at 250 mM NaCl. Shoot length was enhanced by 112% at 500 mM NaCl. Total chlorophyll content increased by 208% at 250 mM NaCl. The chlorophyll a/b ratio increased by 117% at 500 mM. Also, reduced amounts of plant extracts were necessary to scavenge 50% of radicals (−22% at 250 mM compared to the 0 mM control). Proline content increased by 20% at both 250 mM and 500 mM NaCl. These results demonstrate the potential of beneficial bacteria as biostimulants to mitigate salt stress and enhance plant yield in saline soils. Full article

Currently, biostimulants in the horticultural sector are a tool that is being used to improve the yield and quality of vegetables under optimal and stressful growth conditions. In the present study, we evaluate the effects of foliar application of a hydroethanolic extract of Sargassum spp., a commercial extract based on Ascophyllum nodosum, and a control with distilled water on growth and biomass, stomatal conductance, photosynthetic pigments, enzymatic and non-enzymatic antioxidants, protein content, and the expression of defense genes in tomato plants (Solanum lycopersicum L.) without stress and with high-temperature stress (45 °C). The results showed that Sargassum spp. extract only increased the height of tomato plants under stress-free conditions (2.71%) in the last evaluation. The aboveground and total dry biomass of the plants were increased by Sargassum spp. extract under stress-free conditions by 9.56 and 8.58%, respectively. Under stress conditions, aboveground dry biomass was increased by 6.66% by Sargassum spp. extract. Stomatal conductance, photosynthetic pigments, protein content, enzymatic and non-enzymatic antioxidants, and defense gene expression of tomato plants were positively modified with the use of Sargassum spp. and A. nodosum extract under high-temperature stress conditions. Under stress-free conditions, the described variables were positively modified except for gene expression, where some genes were expressed and others were repressed. The results indicate that extracts of Sargassum spp. and A. nodosum are effective in mitigating high-temperature stress, making their use a promising alternative for inducing resistance in plants to the daily adversities of climate change. Full article

Biostimulants based on Bradyrhizobium japonicum are commonly used in soybean production. However, the effect of nitrogen-fixing bacteria in consortia with other plant growth-promoting rhizobacteria (PGPR) and their integration with mineral nutrients on soybean seed quality has not been explored. The study aimed to examine the effects of five treatments on seed germination and initial seedling growth of two soybean cultivars (‘NS Apolo’, ‘NS Rubin’): control (untreated seeds); Br. japonicum (BJ), BJ and nutrient complex (NC), BJ, Azotobacter chroococcum (AC), Bacillus subtilis (BS), and NC; BJ, AC, Bacillus megaterium (BM), and NC. Seed treatments significantly enhanced germination energy, seedling vigor index, root length, fresh shoot weight, fresh root weight, dry shoot weight, and dry root weight of both cultivars, as well as final germination, shoot length, and shoot elongation rate of ‘NS Rubin’, as compared to the control. The highest effect on the investigated parameters was achieved by integrated use of PGPR and nutrients (BJ + BM + AC + NC), indicating that integration of PGPR with a targeted NC represents an innovative approach with practical implications for improving early soybean establishment and field performance. Full article

Sustainable development requires implementation of eco-friendly practices and a circular approach in both agricultural and industrial systems. This study evaluated winery flotation wastewater (WFW) as a cultivation substrate for Bacillus sp. 10/R isolated from grapevine rhizosphere for sustainable biostimulant production. The bacterial isolate was characterized by 16S rRNA sequencing and biochemical tests, showing the highest similarity with Bacillus mojavensis and Bacillus halotolerans. Plant growth-promoting traits were assessed via assays for hydrolytic enzymes, ACC (1-aminocyclopropane-1-carboxylate) deaminase, and IAA (indole acetic acid) production, as well as for phosphate solubilization. The isolate was cultivated in WFW, including monitoring of biomass growth, enzymatic activity, and substrate composition changes. The resulting cultivation broths based on WFW (WFW-CB) and nutrient broth (NB-CB) were tested as barley seed treatment at five dosages, using sterile media and water as controls. The results have displayed strong pectinase (EAI–enzyme activity index 2.79) and cellulase activity (2.33), moderate xylanase (1.75) and ACC deaminase activity (growth zone 54.67 ± 0.58 mm), and moderate IAA production (9.66 µg/mL). Biomass content has increased by two log units within 48 h (up to 9.06 log CFU/mL), with stable pectinase activity (~2.2 U/mL). Germination assays revealed that 10% WFW-CB and 50% WFW enhanced germination indices and biomass, whereas undiluted WFW and WFW-CB inhibited germination. These results indicate that WFW is a suitable substrate for Bacillus sp. 10/R cultivation, linking industrial wastewater valorization with plant biostimulant production in a circular economy framework. Full article

Plant cell wall-derived oligosaccharides, such as xylo-oligosaccharides (XOS), serve as key signaling molecules regulating plant growth and immunity. The bioactivity of XOS is closely tied to their degree of polymerization (DP), yet the molecular mechanisms underlying DP-specific effects remain poorly understood. Here, we investigated the transcriptional and phenotypic responses of lettuce (Lactuca sativa) to foliar application of four high-purity XOS variants: xylobiose (XOSY, DP2), xylotriose (XOSB, DP3), xylotetraose (XOSD, DP4), and xylopentose (XOSW, DP5). Phenotypic analyses revealed that high-DP XOS (XOSD and XOSW) significantly enhanced aboveground biomass and root system development, with XOSD showing the most pronounced effects, including a 31.74% increase in leaf area and a 20.71% increase in aboveground biomass. Transcriptomic profiling identified extensive transcriptional reprogramming across treatments, with XOSD eliciting the highest number of differentially expressed genes (DEGs). Functional enrichment analyses indicated that XOSD and XOSW upregulated genes involved in plant hormone signaling, starch and sucrose metabolism, and cell wall biosynthesis, while downregulating photosynthesis-related genes. Notably, MapMan and KEGG pathway analyses revealed that XOSD significantly activated biotic stress-related pathways, including MAPK signaling, β-1,3-glucanase activity, and PR protein pathways. In contrast, XOSY treatment primarily upregulated genes linked to basal immunity, highlighting distinct mechanisms employed by low- and high-DP XOS. These findings demonstrate that XOS with varying DP differentially modulate growth- and immunity-related processes in lettuce. High-DP XOS, particularly XOSD, not only promote plant biomass accumulation but also enhance immune responses, highlighting their potential as biostimulants for sustainable agriculture. This study provides a molecular framework for understanding the DP-specific bioactivity of XOS and their dual role in optimizing plant growth and defense. Full article

Nowadays, the use of natural biological bio-stimulants such as seaweed extract (SWE) is highly considered for alleviating the adverse effects of drought stress in many plant species. This study evaluated the effects of drought stress and foliar application of seaweed extract (SWE) on the morphological, physiological, and phytochemical traits of Pelargonium graveolens. Three levels of water irrigation regimes were used in combination with four SWE concentrations (0, 2.5, 5, and 7.5 mL L⁻¹). Based on the GC-MS analysis, 83 compounds were identified, of which citronellol, citronellyl formate, α-gurjunene, δ-cadinene, and γ-cadinene were the major constituents of P. graveolens leaves. The highest citronellol content (56.2%) was found under moderate irrigation with 5 mL of L⁻¹ SWE, while the lowest amount (26.78%) was obtained under full irrigation with no foliar application of SWE. Citronellyl formate and α-gurjunene exhibited their highest relative abundance under non-stress conditions following foliar application of 5 mL L⁻¹ and 0 mL L⁻¹ of SWE, respectively. In contrast, δ-cadinene reached its highest value under severe drought stress when treated with 7.5 mL of L⁻¹ SWE, indicating a stress-responsive shift in essential oil (EO) composition profile. Principal component analysis (PCA) revealed that full irrigation with 7.5 mL of L⁻¹ SWE and mild drought with 5 mL of L⁻¹ SWE were the best treatments for ameliorating the EO content and composition. ANOVA revealed that SWE significantly improved the fresh root weight, leaf dimensions, carotenoids, total chlorophyll, protein content, and antioxidant enzyme activities. The 7.5 mL of L⁻¹ SWE treatment notably increased fresh root weight by 29.16% and enhanced chlorophyll and protein levels under moderate and severe drought conditions. Drought stress reduced shoot biomass but had no significant effect on chlorophyll content. Carotenoid and antioxidant activities were significantly influenced by both drought and SWE, with the highest levels observed at 5 mL of L⁻¹ SWE. Antioxidant enzymes (CAT, SOD, and guaiacol peroxidase) and total antioxidant activity were enhanced by SWE and its interaction with drought stress conditions. These results suggest that foliar SWE application at 5–7.5 mL L⁻¹ effectively mitigates drought stress and enhances both growth and EO composition in P. graveolens. Full article

The genus Hippeastrum (Amaryllidaceae) is very popular worldwide for its attractive, colourful flowers. The aim of the research was to evaluate the possibility of replacing synthetic growth regulators added to the media with biostimulants of natural origin on the micropropagation and acclimatisation efficiency of several Hippeastrum genotypes. The effect of the biostimulants on the starch and fructan content of the bulbils after a 10-week in vitro culture was also investigated. The addition of biostimulant Goteo to the MS medium in vitro resulted in increased plantlet weight, leaf length and root number for most of the genotypes tested. The Folium biostimulant, not previously used in in vitro plant culture media showed positive effects, especially on leaf length. The use of Goteo during plant acclimatisation significantly improved root growth parameters, indicating its potential in minimising stress associated with the change from in vitro to ex vitro conditions. Higher starch content was detected in the bulbils of clone 0017-01 and the highest fructan content in the bulbils of clone 18 H. × chmielii. The use of the Folium biostimulant, consisting mainly of amino acids, reduced sugar accumulation, which may have been due to a shift in carbon allocation from storage processes to photosynthesis. The results confirm that biostimulants based on natural ingredients can be an alternative to synthetic growth regulators in the micropropagation of Hippeastrum and possibly other ornamental plants, what will be an input to further development of sustainable horticulture production. Full article

Halotolerant endophytic fungi (HEFs) represent a critical biological resource in mitigating plant salt–alkali stress, demonstrating remarkable adaptability across diverse ecological environments. This comprehensive review analyzes 150 scientific publications, revealing HEFs’ multifaceted mechanisms of plant stress tolerance. Inhabiting over 30 host plant species without causing pathogenic effects, these fungi enhance plant resilience through sophisticated physiological strategies. Key findings highlight HEFs’ ability to modulate ionic homeostasis, elevate antioxidant capacities, and stimulate plant growth under saline conditions. The research unveils the potential of HEF metabolites as biostimulants and explores their co-evolutionary hypotheses with host plants. Despite promising laboratory and field validations, significant challenges remain in HEFs’ practical agricultural applications, including environmental factor interactions and biotechnological ethical considerations. Future research directions emphasize deeper investigations into HEFs’ ecological adaptability and microbiological interactions to unlock their full agricultural potential. Full article