Search Results (102)

This research evaluated the efficacy of using two types of biochar (non-modified and acidified) from date palm residues (fronds, leaves, pits) as soil amendments for enhancing soil fertility and maize growth. These biochars were produced through slow pyrolysis under oxygen-limited conditions at 500 °C. Our innovative approach was to minimize gas emissions by converting smoke into liquid fertilizer (LS), which was expected to improve seed germination and early plant growth stages. To assess this aim, a completely randomized experiment was conducted under lab conditions, in which 10 maize seeds were placed on double filter papers in Petri dishes and then exposed to seven concentrations of LS (0.0, 0.01, 0.10, 1.0, 10 and 100%, using distilled water for dilution v/v). The LS contains nutrients and bioactive compounds that may enhance seed germination and early plant growth at low concentrations, whereas higher concentrations may cause phytotoxic effects. Results showed that liquefied smoke at 0.1% increased the absolute percentage of maize germination from 75% (control) to 100% and achieved the highest root length of 9.80 cm. Acidified biochars at 5% reduced soil pH from 8.87 to 8.12 and enhanced potassium availability to 87.93 mg kg⁻¹. Conversely, the non-modified biochars contributed to further increases in soil organic matter (up to 1.02%), nitrogen, and phosphorus. In addition, the application of acidified leaf biochar (5%) enhanced maize shoot growth by 133%, chlorophyll content by 39%, and potassium uptake by 110%. This research establishes a scalable approach for converting agricultural waste into climate-resilient resources, effectively addressing soil degradation in arid environments, boosting crop resilience, and furthering the objectives of a circular bioeconomy. Full article

Modern agriculture faces significant challenges, such as population growth, the reduction in productive agricultural land, and, most importantly, climate change. To address these issues, non-thermal plasma treatment of seeds and plants has emerged as a promising alternative to conventional chemical-based methods. This advanced technology, a powerful chemical reactor in the gas phase, has various applications, from stimulating seed germination and plant growth to controlling pathogens. The effects of non-thermal plasma on seeds include morphological and chemical changes in the seed coat, increased permeability and water uptake, and the activation of some internal biochemical mechanisms. Studies have demonstrated improvements in germination, plant development, and the activation of internal biochemical mechanisms with the intensified production of secondary metabolites. Non-thermal plasma also contributes to reducing the microbial load, providing an effective and environmentally friendly method of disinfection. This review synthesises the current knowledge on non-thermal plasma sources used in plasma agricultural applications for seed treatments, emphasising that in some cases the exposure of seeds to such discharge stimulates germination and also promotes early seedling growth. In addition, it highlights reported biochemical and nutraceutical improvements, including changes in antioxidant capacity, phenolic content and other bioactive compounds which add considerable value to the resulting plants. Finally, the decontamination potential is discussed, along with results discussing the potential of NTP to decontaminate seeds, associated with an extension to the shelf-life of products and identifying key challenges and research gaps for implementing this technology in agricultural practices. The integration of this technology into modern agriculture, including vertical farms and hydroponic systems, opens up the prospect for more sustainable and productive agriculture. However, scaling up the process and optimising processing parameters remain important challenges that require further attention, research and technological development. Full article

Lisianthus [Eustoma grandiflorum (Raf.) Shinners] is among the 10 most produced and marketed cut flowers in the world. However, its slow growth represents a challenge for its production. This study evaluated the efficiency of rhizobacterial strains in vegetative growth and nutrient acquisition in lisianthus plants. Freshly germinated seeds of lisianthus cv. Mariachi Blue Double were used. Seven rhizobacterial strains and two controls (sterile distilled water and nutrient broth) were evaluated in a completely randomized design. Replication varied among treatments and variables: shoot growth traits were assessed on 10–12 plants per treatment, root biomass on a destructive subsample of six plants per treatment and shoot nutrient contents on four composite samples per treatment. Measurements taken 149 days after sowing showed that plants inoculated with the strains Acinetobacter vivianii C48, Achromobacter xylosoxidans C56, and Arthrobacter pokkalii JLB4 had greater height, leaf area, leaf number, and fresh and dry biomass, both aerial and in the root. These strains also enhanced N and P uptake in shoot tissues. In contrast, the Bacillus pumilus strain R44 significantly decreased height and leaf number. The results suggest that strains C48, C56 and JLB4 can stimulate nutrition, accelerate plant growth, and shorten the vegetative phase in lisianthus. Full article

Salinity stress constitutes a major environmental constraint impeding crop establishment by limiting water uptake and disrupting osmotic homeostasis during seed germination and early growth. Plant growth-promoting bacteria (PGPB) offer as a sustainable and cost-effective strategy to mitigate these limitations in agricultural systems. In this study, whole-genome analysis of the salt-tolerant PGPB Priestia aryabhattai WJ45 identified its genomic potential for PGP and salinity adaptation, alongside evaluations of wheat germination under saline conditions. Genome analysis revealed that strain WJ45 harbors a coordinated set of genes associated with key plant growth-promoting traits, including exopolysaccharide production, phosphate solubilization, and siderophore biosynthesis, as well as genes involved in Na⁺/K⁺ transport and osmolyte metabolism. Consistent with these genomic predictions, germination assays demonstrated that WJ45 treatment increased the germination rate by 13.1%, under salt stress compared with the non-inoculated control, while coleoptile, radicle lengths, and fresh weight were enhanced by 17.0%, 15.7%, and 53.2%, respectively, indicating improved early seedling establishment. Collectively, these findings demonstrate that WJ45 possesses a genome-encoded capacity to facilitate crop establishment under saline conditions. While further seedling and large-scale evaluations are warranted, this study underscores the potential of this genome-informed microbial resource to enhance early plant growth and resilience in salt-affected environments. Full article

The invasive weed Malachra capitata is unsuitable for human or animal consumption but has recently attracted attention for potential alternative uses. In this study, the allelopathic potential of M. capitata for weed control was investigated, as were its allelopathic effects on selected crops. The influence of plant developmental stage on its phytotoxic activity was also assessed. In addition, the physiological effects of the extract on seed germination were investigated. Aqueous leaf extracts were obtained across a range of growth stages and evaluated using seed germination and seedling growth bioassays, followed by bioassay-guided fractionation and GC-MS analysis. Leaves extracts collected at 35 days after planting exhibited the strongest inhibitory activity. Dicot plant species (Phaseolus lathyroides, Cucumis sativus, Brassica oleracea, and B. chinensis) were more susceptible to M. capitata extracts than grassy species (Echinochloa crus-galli, Zea mays, and Oryza sativa), indicating selective phytotoxicity. In pot experiments, application of leaf residues as surface mulch at rates of 100, 200, and 400 g/m² significantly reduced P. lathyroides emergence by 11.25%, 35.00%, and 71.25%, respectively. Bioassay-guided fractionation indicated the ethyl acetate-soluble acidic fraction to contain the active allelochemicals. This inhibition was associated with reduced water uptake and suppression of α-amylase activity during seed germination. The most abundant GC-MS detectable components of the acidic fraction were octadecane (12.45%), eicosane (9.74%), and hexadecane (9.60%). Overall, these findings highlight the allelopathic potential of M. capitata, providing a foundation for further applied research and supporting its valorization for sustainable weed management. Full article

Cremastra appendiculata, a rare medicinal orchid, has extremely low natural seed germination due to immature embryos and dense seed coats, impeding its conservation. Commensal germination with fungi is effective, but the action pathways remain unclear. This study combined morphological observation (scanning electron microscopy and section observation), physiological–biochemical detection (lignocellulolytic enzyme activities, nutrient/hormone contents, FTIR analysis) and transcriptomics to explore Coprinellus radians’ role in C. appendiculata seed germination, with commensal and non-commensal cultures on OMA medium set as experimental and control groups. Results showed C. radians significantly promoted C. appendiculata seed germination and protocorm development (superior to non-commensal conditions). Morphologically, C. radians hyphae invaded seed coats at 6 days post-inoculation; embryos broke through coats and formed apical meristems at 12 days, developing into peloton-containing protocorms at 25 days (breaking dormancy). Physiologically, C. radians secreted lignocellulolytic enzymes (laccase, cellulase, xylanase) to degrade coats, enhancing permeability and water uptake, while driving nutrient accumulation (starch, soluble sugars) and hormone balance. Transcriptomically, symbiosis activated carbon/energy metabolism genes, enriching starch-sucrose metabolism and glycolysis pathways. This study clarifies C. radians’ multi-dimensional action pathways in promoting C. appendiculata germination, providing support for rare orchid conservation. Full article

Soil salinity is a major abiotic stress that limits rice production, with severity varying among genotypes. It disrupts key physiological processes, particularly water uptake and membrane integrity. This study evaluated six rice genotypes to (i) determine the critical salinity threshold for seed germination and (ii) investigate the physiological mechanisms underlying genotypic variation. Seeds were exposed to saline solutions of up to 32 dS m⁻¹ under controlled conditions, and germination was recorded at 2, 5, 10, and 14 days after stress imposition. Additional assays at 0, 12, 18, and 24 dS m⁻¹ for 1, 3, and 5 days assessed water uptake, electrolyte leakage, and malondialdehyde (MDA) accumulation. The critical threshold for germination was consistent across genotypes (26.01–28.53 dS m⁻¹), except for Nona Bokra, which was more sensitive (20.5 dS m⁻¹). Salinity reduced seed water uptake and promoted membrane degradation, as evidenced by increased electrolyte leakage and MDA accumulation, with severity proportional to stress duration. Full article

Applying non-thermal plasma (NTP) to seeds prior to sowing is recognized for its ability to enhance germination and promote plant growth. This study investigated the effects of NTP seed treatment on alfalfa seed surface characterization, germination, growth, and biochemical traits under varying water conditions. NTP modified seed surface properties by decreasing water contact angle, roughening the coat, and reducing O–H/N–H and C–H band intensities, while major functional groups remained intact. Short plasma exposures (<2 min) enhanced germination, whereas prolonged treatment (10 min) reduced viability, indicating embryo sensitivity. In pot experiments, both 1 and 5 min treatments improved fresh and dry weight, stem and root elongation, pigment accumulation, and protein content, particularly under normal and moderate water stress, while extended exposure (10 min) offered limited benefits and could be detrimental under severe drought. Root growth was most responsive, suggesting enhanced water and nutrient uptake. Plasma had modest effects on polyphenols and flavonoids but influenced early physiological responses and antioxidant activity. These findings highlight NTP as a promising seed priming tool to improve alfalfa performance, though further studies are needed to clarify the mechanisms and specific contributions of plasma components. Full article

Soil salinity poses a major threat to agriculture by severely limiting how well plants grow and produce crops. It strongly inhibits seed germination, a critical stage for plant life. Thus, it is critical to understand the complex ways salinity affects seed germination at the physiological, biochemical, and molecular levels to develop effective salt stress mitigation strategies. This review synthesizes the underlying mechanisms of how salinity inhibits seed germination, the observed impacts of this inhibition, and potential mitigation strategies. The review revealed that high salt concentrations reduce seed germination percentage and increase germination time through multiple mechanisms. They create osmotic stress that reduces water uptake, cause ion toxicity that disrupts critical metabolic activities, and induce oxidative stress. Furthermore, salinity can modify endogenous hormonal profiles, specifically by decreasing germination stimulants like gibberellic acids while increasing inhibitors like abscisic acid. The review finally explored the strategies to mitigate salinity’s adverse effects on seed germination. They include seed priming, a technique involving partial hydration of seeds in an eliciting solution, a promising biotechnological tool to overcome salinity problems during seed germination. Other approaches are the use of organic amendments and the breeding of salt-tolerant varieties. Future research should combine conventional and advanced molecular technologies to develop salt-tolerant cultivars to ensure food security in salt-affected agricultural lands. Full article

Heavy metal (HM) contamination threatens environmental sustainability, food safety, and agricultural productivity worldwide. HM toxicity adversely affects plant growth, reducing germination rates by 20–50%, impairing seedling establishment, and inhibiting shoot and root development by 30–60% in various crops. HM disrupts key physiological processes, including photosynthesis, stomatal regulation, membrane integrity, nutrient uptake, and enzymatic and nonenzymatic antioxidant activities. These disruptions largely result from oxidative stress, caused by the excessive accumulation of reactive oxygen species, which damage cellular components. To counteract HM toxicity, plants deploy a complex defense network involving antioxidant enzymes, metal chelation by phytochelatins and metallothioneins, vacuolar sequestration, and symbiotic interactions with arbuscular mycorrhizal fungi, which can retain 40–70% of metals in roots and reduce translocation to shoots. At the molecular level, MAPK (Mitogen-Activated Protein Kinase) signaling pathways, transcription factors (e.g., WRKY, MYB, bZIP, and NAC), and phytohormonal crosstalk regulate the expression of stress-responsive genes expression to enhance HM stress tolerance. Advances in nanotechnology offer promising strategies for the remediation of HM-contaminated soils and water sources (HM remediation); engineered and biogenic nanoparticles (e.g., ZnO, Fe₃O₄) improve metal immobilization, reduce bioavailability, and enhance plant growth by 15–35% under HM stresses, although excessive doses may induce phytotoxicity. Future applications of nanotechnology in HM remediation should consider nanoparticle transformation (e.g., dissolution and agglomeration) and environmentally relevant concentrations to ensure efficacy and minimize phytotoxicity. Integrating phytoremediation with nanoparticle-enabled strategies provides a sustainable approach for HM remediation. This review emphasizes the need for a multidisciplinary framework linking plant science, biotechnology, and nanoscience to advance HM remediation and safeguard agricultural productivity. Full article

Foxtail millet is a plant that is highly drought-resistant and rich in nutrients. Its grain structure traits are linked with water uptake during grain germination, which is closely related to plant density for high yield under rain fed regions; however, there is no related research. Using Micro-CT technology, we investigated a total of 15 internal structure traits of foxtail millet grains, such as the volume and surface area of the embryo, endosperm, cavity, hull, and whole grain, and mapped relevant quantitative trait loci (QTLs) using recombination inbred lines (RILs). With phenotypic variations in these traits and genome sequences of 100 foxtail millet RILs, four QTLs were identified. In combination with transcriptome profiling during grain development, we identified seven candidate genes that may play a role in the regulation of grain structure in foxtail millet. Full article

Eutrophication caused by excessive nitrogen (N) and phosphorus (P) inputs threatens aquatic ecosystems and requires sustainable solutions. Barley (Hordeum vulgare L.) is a fast-growing forage crop with potential for removing nutrients in eutrophic waters; however, a comprehensive understanding of its physiological responses across a wide gradient of concurrent N and P levels is still developing. To investigate this, a 7-day hydroponic experiment was conducted: six N + P enrichment levels, control (0), 70 + 7, 140 + 14, 280 + 28, 560 + 56, and 1120 + 112 mg·L^–1 of total N and P (TN:TP fixed at 10:1), were prepared in hydroponic culture and their effect on seed germination, growth, nutritional quality, photosynthetic pigments, antioxidant activity, and nutrient removal efficiency were studied. Results showed that early germination was inhibited under nutrients and enriched conditions, but this recovered by day 3. A moderate nutrient supply (NP 70 + 7) promoted seedling growth, resulting in maximum plant height, fresh weight, crude protein (6.6%), ether extract (6.1%), and chlorophyll a (10.9%) compared to the control. Root growth was best in control, while high nutrient stress (NP 1120 + 112) led to the highest mortality (23.5%). This mortality was linked to a severe suppression of the enzymatic antioxidant system (SOD, POD, and CAT), indicating a collapse of primary oxidative defense under extreme stress. Nutritional quality improved under NP 140 + 14, which yielded the lowest NDF and ADF and the highest chlorophyll b (15%) and glutathione content (14.9%). Antioxidant enzymes (SOD, POD, and CAT) were most active in the control and declined with increasing N + P levels, while glutathione peaked under NP 140 + 14. This indicates a potential shift in the plant’s defense strategy, where glutathione plays a key role in mediating tolerance to moderate eutrophic stress. Nutrient removal analysis showed that N removal efficiency was highest under NP 70 + 7 (53.4%), whereas P removal decreased consistently with rising concentrations. Overall, barley grass seedlings tolerated N + P levels up to NP 280 + 28 while maintaining growth and nutrient uptake, a resilience facilitated by its dynamic antioxidant response, suggesting their potential role in phytoremediation of eutrophic waters. Full article

Ultrafine bubble (UFB) priming has recently emerged as a promising technique to enhance seed germination, yet its physiological mechanisms remain unclear. This study investigated the effects of UFB priming on adzuki bean (Vigna angularis) seeds under stress-free and drought conditions. Four treatments were tested: Control (non-primed), DW (primed with distilled water), UFB1 (4.56 × 10⁷ particles/mL), and UFB2 (1.13 × 10⁸ particles/mL). For priming, seeds were immersed in each solution at 25 ± 1 °C for 24 h. Seed traits, including water uptake, coat thickness, and total reactive oxygen species (ROS) levels in the priming solutions and seeds, were analyzed. UFB priming reduced seed coat thickness and slowed early water uptake without affecting final moisture content. Total ROS levels displayed a concentration-dependent pattern, with higher UFB increasing ROS in water but reducing them on the seed surface. Under stress-free conditions, all priming treatments accelerated germination, although higher UFB slightly prolonged T50. Under drought simulated by polyethylene glycol (PEG 10 and 15%), non-primed seeds were strongly inhibited, whereas primed seeds maintained high germination rates (>97%). Our results demonstrated that UFB priming improved water uptake, seed coat structure, and ROS signaling, enhancing seed performance of adzuki bean under favorable and drought conditions. Full article

Global temperature rise has become a critical challenge to agricultural sustainability, severely affecting crop growth, productivity, and survival. Human-induced climate change and greenhouse gas emissions cause heat stress, disrupting plant metabolism and physiology at all developmental stages from germination to harvest. Elevated temperatures during germination impair water uptake, enzyme activity, and energy metabolism, leading to poor or uneven seedling emergence. At key phases such as flowering and grain filling, heat stress limits photosynthesis and transpiration by inducing stomatal closure, restricting carbon dioxide intake, and reducing photosynthetic efficiency. The reproductive stage is particularly vulnerable to high temperatures, impairing pollen viability, preventing anther dehiscence, and reducing fertilization success. Membrane instability further accelerates chlorophyll degradation and leaf senescence. Heat stress also alters biochemical and hormonal balances by disrupting the synthesis and signaling of auxins, gibberellins, and abscisic acid (ABA). Elevated ABA promotes stomatal closure to enhance stress tolerance, while increased ethylene levels trigger premature leaf senescence and abscission. These hormonal shifts and oxidative stress hinder plant growth and reproduction, threatening global food security. Although plants employ adaptive mechanisms such as heat shock protein expression and stress-responsive gene regulation, current strategies remain inadequate, highlighting the urgent need for innovative approaches to improve crop resilience under rising temperatures. Full article

The increasing demand for sustainable substrates in agriculture and urban greening calls for alternatives to peat, whose extraction poses significant environmental risks. This study assesses the potential of olive pomace biochar (OB), wood biochar (WB), and green compost (GC), alone or in combination, to partially replace peat in growing media and improve substrate properties and plant development. Ten different substrates were formulated by substituting 10–20% of a commercial peat-based substrate with these organic amendments, using the commercial substrate alone as a control. The effects of such replacements were evaluated in the following experiments: a germination test conducted in Petri dishes using four forage species (Medicago polymorpha, Lolium perenne, Festuca arundinacea, and Lolium rigidum); and two parallel pot experiments lasting 100 days each (one with M. polymorpha and L. perenne, and another with young Olea Europaea var. Arbequina saplings). This study evaluated the impact on plant development, as well as the physical properties and composition of the substrates during the incubation process. Germination and survival of forage species were comparable or improved in most treatments, except those including 20% OB, which consistently reduced germination—likely due to high electrical conductivity (>10dS/m). In the pot experiments, substrate pH and total carbon content increased significantly with biochar addition, particularly with 20% WB, which doubled total C relative to control. Both forage species (Medicago polymorpha and Lolium perenne) and the olive saplings (Olea Europaea) exhibited normal growth, with no significant differences in biomass, water content, or physiological stress indicators when compared to the control group. Nutrient uptake was found to be stable across treatments, although magnesium levels were below sufficiency thresholds without triggering visible deficiency symptoms. Overall, combining compost and biochar—particularly WB and GC—proved to be a viable strategy to reduce peat use while maintaining substrate quality and supporting robust plant growth. This approach proved effective across the different plant varieties tested, including Medicago polymorpha, Lolium perenne, and young olive plants, which together encompass a wide spectrum of agronomic and horticultural applications as well as contrasting growth and nutrient requirements. Adverse effects on early plant development can be avoided by carefully selecting and characterizing biochars, with specific attention to salinity and C/N ratio. This finding is crucial for the successful large-scale implementation of sustainable alternatives to peat. Full article