Search Results (982)

Common bean (Phaseolus vulgaris L.) is a critical protein-rich legume supporting food and nutritional security globally. However, Fusarium wilt, caused by Fusarium solani, remains a major constraint to production, with yield losses reaching up to 84%. While biocontrol strategies have been explored, most microbial agents are sourced from mesophilic environments and show limited effectiveness under abiotic stress. Here, we report the isolation and characterization of extremophilic Bacillus spp. from the hypersaline Lake Bogoria, Kenya, and their biocontrol potential against F. solani. From 30 isolates obtained via serial dilution, 9 exhibited antagonistic activity in vitro, with mycelial inhibition ranging from 1.07-1.93 cm 16S rRNA sequencing revealed taxonomic diversity within the Bacillus genus, including unique extremotolerant strains. Molecular screening identified genes associated with the biosynthesis of antifungal metabolites such as 2,4-diacetylphloroglucinol, pyrrolnitrin, and hydrogen cyanide. Enzyme assays confirmed substantial production of chitinase (1.33–3160 U/mL) and chitosanase (10.62–28.33 mm), supporting a cell wall-targeted antagonism mechanism. In planta assays with the lead isolate (B7) significantly reduced disease incidence (8–35%) and wilt severity (1–5 affected plants), while enhancing root colonization under pathogen pressure. These findings demonstrate that extremophile-derived Bacillus spp. possess robust antifungal traits and highlight their potential as climate-resilient biocontrol agents for sustainable bean production in arid and semi-arid agroecosystems. Full article

Soil degradation resulting from intensive agricultural practices, the excessive use of agrochemicals, and climate-induced stresses has significantly impaired soil fertility, disrupted microbial diversity, and reduced crop productivity. Plant growth-promoting bacteria (PGPB) represent a sustainable biological approach to restoring degraded soils by modulating plant physiology and soil function through diverse molecular mechanisms. PGPB synthesizes indole-3-acetic acid (IAA) to stimulate root development and nutrient uptake and produce ACC deaminase, which lowers ethylene accumulation under stress, mitigating growth inhibition. They also enhance nutrient availability by releasing phosphate-solubilizing enzymes and siderophores that improve iron acquisition. In parallel, PGPB activates jasmonate and salicylate pathways, priming a systemic resistance to biotic and abiotic stress. Through quorum sensing, biofilm formation, and biosynthetic gene clusters encoding antibiotics, lipopeptides, and VOCs, PGPB strengthen rhizosphere colonization and suppress pathogens. These interactions contribute to microbial community recovery, an improved soil structure, and enhanced nutrient cycling. This review synthesizes current evidence on the molecular and physiological mechanisms by which PGPB enhance soil restoration in degraded agroecosystems, highlighting their role beyond biofertilization as key agents in ecological rehabilitation. It examines advances in nutrient mobilization, stress mitigation, and signaling pathways, based on the literature retrieved from major scientific databases, focusing on studies published in the last decade. Full article

Nitrogen (N) availability often limits primary productivity in terrestrial ecosystems, and arbuscular mycorrhizal fungi (AMF) can enhance plant N acquisition. This study investigated the interactive effects of N fertilization and AMF inoculation on N uptake, plant performance and phenolic acid content in Hyssopus officinalis L., with the aim of promoting sustainable N management in H. officinalis cultivation. A factorial randomized complete block design was employed to evaluate four AMF inoculation strategies (no inoculation, root inoculation, soil inoculation and combined root–soil inoculation) across three N application rates (0, 0.5 and 1,1 g N pot⁻¹ (7 L)) in a controlled greenhouse environment. Combined root and soil AMF inoculation alongside moderate N fertilization (0.5 mg N pot⁻¹) optimized N use efficiency, maximizing plant biomass and bioactive compound production. Compared to non-inoculated controls, this treatment combination increased N uptake by 30%, phosphorus uptake by 24% and potassium uptake by 22%. AMF colonization increased chlorophyll content and total phenolic compounds under moderate N supply. However, excessive N application (1 g N pot⁻¹) reduced AMF effectiveness and secondary metabolite accumulation. Notably, AMF inoculation without N fertilization yielded the highest levels of anthocyanin and salicylic acid, indicating differential N-dependent regulation of specific biosynthetic pathways. The interaction between AMF and N demonstrated that moderate N fertilization (0.5 g N pot⁻¹) combined with dual inoculation strategies can reduce total N input requirements by 50%, while maintaining optimal plant performance. These findings provide practical insights for developing N-efficient cultivation protocols in medicinal plant production systems, contributing to sustainable agricultural practices that minimize environmental N losses. Full article

Reducing the application of chemical fertilizers and remediating heavy metal pollution in soil are important directions in current agricultural research. Utilizing the plant-growth-promoting and remediation capabilities of bacteria can provide more environmentally friendly assistance to agricultural production. In this study, the Burkholderia alba YIM B08401 strain was isolated and identified from rhizospheric soil, subjected to whole-genome sequencing and analysis, and its Cd²⁺ adsorption efficiency and characteristics were confirmed using multiple experimental methods, including atomic absorption spectrometry (AAS), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS). The results showed that the genome of strain YIM B08401 has a total length of 7,322,157 bp, a GC content of 66.39%, and predicts 6504 protein-coding sequences. It contains abundant functional genes related to nutrient conversion (phosphate solubilization, sulfur metabolism, zinc solubilization, siderophore production), plant hormone regulation (indole-3-acetic acid secretion, ACC deaminase production), phenolic acid degradation, root colonization, heavy metal tolerance, pathogen antagonism, and the production of antagonistic secondary metabolites. Additionally, strain YIM B08401 can specifically bind to Cd²⁺ through various functional groups on the cell surface, such as C-O-C, P=O, and O-H, enabling biosorption. In conclusion, strain YIM B08401 is an excellent strain with plant-growth-promoting, disease-resistant, and bioremediation capabilities, warranting further development as a biofertilizer for agricultural applications to promote green and sustainable agricultural development. Full article

Meloidogyne enterolobii, a highly virulent and broad-host-range plant-parasitic nematode, poses an increasing threat to global agricultural production. By inducing the formation of nutrient-rich giant cells in host roots and deploying a diverse array of effector proteins to modulate plant immune responses, this nematode achieves efficient colonization and invasion, resulting in impaired crop growth and significant economic losses. In recent years, global climate warming combined with the rapid development of protected agriculture has broken the traditional geographical limits of tropical and subtropical regions, thereby increasing the risk of M. enterolobii occurrence in temperate and high-latitude areas. Concurrently, conventional chemical control methods are increasingly limited by environmental pollution and the development of resistance, steering research toward green control strategies. This review systematically summarizes the latest research progress of M. enterolobii in terms of ecological diffusion trends, pathogenic mechanisms, and green control, and explored the feasibility of integrating multidisciplinary technologies to construct an efficient and precise control system. The ultimate aim is to provide theoretical support and technical supports for green and sustainable development of global agriculture. Full article

Azospirillum is a well-studied genus of plant growth-promoting rhizobacteria (PGPR) and one of the most extensively researched diazotrophs. This genus can colonize rhizosphere soil and enhance plant growth and productivity by supplying essential nutrients to the host. Azospirillum–plant interactions involve multiple mechanisms, including nitrogen fixation, the production of phytohormones (auxins, cytokinins, indole acetic acid (IAA), and gibberellins), plant growth regulators, siderophore production, phosphate solubilization, and the synthesis of various bioactive molecules, such as flavonoids, hydrogen cyanide (HCN), and catalase. Thus, Azospirillum is involved in plant growth and development. The genus Azospirillum also enhances membrane activity by modifying the composition of membrane phospholipids and fatty acids, thereby ensuring membrane fluidity under water deficiency. It promotes the development of adventitious root systems, increases mineral and water uptake, mitigates environmental stressors (both biotic and abiotic), and exhibits antipathogenic activity. Biological nitrogen fixation (BNF) is the primary mechanism of Azospirillum, which is governed by structural nif genes present in all diazotrophic species. Globally, Azospirillum spp. are widely used as inoculants for commercial crop production. It is considered a non-pathogenic bacterium that can be utilized as a biofertilizer for a variety of crops, particularly cereals and grasses such as rice and wheat, which are economically significant for agriculture. Furthermore, Azospirillum spp. influence gene expression pathways in plants, enhancing their resistance to biotic and abiotic stressors. Advances in genomics and transcriptomics have provided new insights into plant-microbe interactions. This review explored the molecular mechanisms underlying the role of Azospirillum spp. in plant growth. Additionally, BNF phytohormone synthesis, root architecture modification for nutrient uptake and stress tolerance, and immobilization for enhanced crop production are also important. A deeper understanding of the molecular basis of Azospirillum in biofertilizer and biostimulant development, as well as genetically engineered and immobilized strains for improved phosphate solubilization and nitrogen fixation, will contribute to sustainable agricultural practices and help to meet global food security demands. Full article

The Tetranychus urticae Koch (Acari: Tetranychidae) is one of the primary pests affecting buckwheat, and its management has become increasingly critical. Entomopathogenic fungi offer a promising way to solve this problem by providing both pest control and disease resistance, as well as promoting plant growth through endophytic colonization. This study investigated the effects of applying Isaria cateniannulata (Liang) Samson & Hywel-Jones and Beauveria bassiana (Bals.-Criv.) Vuill. on different buckwheat varieties, and analyzed the physiological indices of buckwheat, the population of T. urticae and Euseius nicholsi (Ehara & Lee). Results showed that the optimum concentration for fungal colonization on buckwheat was 1 × 10⁷ spores/mL. The combined application of I. cateniannulata and B. bassiana significantly enhanced buckwheat growth, with root length, plant height, main stem diameter, fresh weight, and dry weight reaching 63.3 mm, 24.1 cm, 2.1 mm, 2.0 g, and 0.1 g, respectively. The highest escape rate of T. urticae was 76.33%. Furthermore, the combined application of mixed fungal suspension and E. nicholsi had the best control effect on T. urticae, with pest suppression exceeding 97.83% and an oviposition as low as 0.25 eggs per female. This study is the first to demonstrate that the joint application of I. cateniannulata and B. bassiana can promote buckwheat growth and, when combined with predatory mites, effectively control T. urticae. These findings provide a theoretical basis for the development of integrated biocontrol strategies combining entomopathogenic fungi and predatory mites. Full article

Soil salinization poses a critical threat to global agriculture, necessitating innovative strategies for sustainable remediation. This review synthesizes advances in leveraging plant–microbe interactions to remediate saline–alkali soils, focusing on oilseed crops—Brassica napus, Glycine max, Arachis hypogaea, Helianthus annuus, and Sesamum indicum—as keystone species for ecosystem restoration. These crops exhibit unique adaptive strategies, including root architectural plasticity and exudate-mediated recruitment of stress-resilient microbiomes (Proteobacteria, Actinobacteria, and Ascomycota), which collectively stabilize soil structure and enhance nutrient cycling, ion homeostasis, and soil aggregation to mitigate soil salinity and alkalinity. Emerging technologies further amplify these natural synergies: nanomaterials optimize nutrient delivery and microbial colonization, while artificial intelligence (AI) models predict optimal plant growth-promoting rhizobacteria (PGPR) combinations and simulate remediation outcomes. This integration establishes a roadmap for precision microbiome engineering, offering scalable strategies to restore soil health and ensure food security in saline–alkali ecosystems. Full article

Clubroot, caused by Plasmodiophora brassicae Woronin, poses a major threat to Chinese cabbage (Brassica rapa subsp. pekinensis) production worldwide, significantly impacting crop yield, quality, and economic value. Biological control represents a promising approach since it is non-toxic and eco-friendly, and it reduces the risk of pathogen resistance development. In this study, our objective was to screen for actinomycetes that can effectively inhibit clubroot. We screened 13 actinomycete strains, identifying 2, XDS3-6 and CD1-1, with substantial in vivo inhibitory effects, achieving infection suppression rates above 64% against P. brassicae. Phylogenetic analysis classified XDS3-6 and CD1-1 as Streptomyces virginiae and Streptomyces cinnamonensis, respectively. Both strains exhibited protease and glucanase production capabilities, essential for pathogenic suppression. Additionally, these strains induced host defense responses, as evidenced by increased jasmonic acid (JA) and salicylic acid (SA) accumulation and elevated activities of defense-related enzymes. Colonization studies of XDS3-6 and CD1-1 mutant strains in cabbage roots indicated sustained root colonization, with peak colony-forming units (CFUs) at 20 days post-inoculation, reaching 11.0 × 10⁴ CFU/g and 8.5 × 10⁴ CFU/g, respectively, and persisting for at least 30 days. Overall, these findings underscore the potential of Streptomyces strains XDS3-6 and CD1-1 as effective biocontrol agents, providing a theoretical foundation for their application in managing clubroot in Chinese cabbage. Full article

The utilization of the widely distributed saline–alkali lands by planting forage grasses is a hot topic. However, the promotion of plant growth remains a great challenge during the exploration of this stressful soil. While halotolerant bacteria are beneficial for plants against saline–alkali stress, their stable colonization on plant roots should be further strengthened. In this study, we investigated the effect of moss biochar on the root colonization of the exogenous halotolerant Halomonas salifodinae isolated from saline lake sediments. During the incubation with the bacteria, the biochar strongly bound the bacterium and induced biofilm formation on the biochar surface. When the biochar and the bacterium were added into the culturing soil of the forage grass Medicago sativa, the biochar remarkably assisted the root binding and biofilm formation of this bacterium on the plant roots. Under the biochar–bacterium combined treatment, the numbers of total bacteria, halotolerant bacteria, and nitrogen-fixing bacteria increased from 10^5.5 CFU/g soil to 10^7.2 CFU/g soil, from 10^4.5 CFU/g soil to 10^6.1 CFU/g soil, and from 10^4.7 CFU/g soil to 10^6.3 CFU/g soil, respectively. After 30 days of culturing, the biochar and the bacterium in combination increased the plant height from 10.3 cm to 36 cm, and enhanced the accumulation of chlorophyll a, reducing sugars, soluble proteins, and superoxide dismutase in the leaves. Moreover, the combined treatment increased the activity of soil enzymes, including peroxidase, alkaline phosphatase, and urease. Meanwhile, the levels of various cations in the rhizosphere soil were reduced by the combined treatment, e.g., Na⁺, Cu²⁺, Fe²⁺, Mg²⁺, Mn²⁺, etc., indicating an improvement in the soil quality. This study developed the biochar–halotolerant bacterium joint strategy to improve the yield of forage grasses in saline–alkali soil. Full article

Arbuscular mycorrhizal fungi (AMF) symbiosis has great potential in improving grapevine performance and reducing external input dependency in viticulture. However, the precise, strain-specific impacts of different AMF species on ‘Summer Black’ grapevine cuttings across multiple physiological and morphological dimensions remain underexplored. To address this, we conducted a controlled greenhouse pot experiment, systematically evaluating four different AMF species (Diversispora versiformis, Diversispora spurca, Funneliformis mosseae, and Paraglomus occultum) on ‘Summer Black’ grapevine cuttings. All AMF treatments successfully established root colonization, with F. mosseae achieving the highest infection rate. In detail, F. mosseae notably enhanced total root length, root surface area, and volume, while D. versiformis specifically improved primary adventitious and 2nd-order lateral root numbers. Phosphorus (P) uptake in both leaves and roots was significantly elevated across all AMF treatments, with F. mosseae leading to a 42% increase in leaf P content. Furthermore, AMF inoculation generally enhanced the activities of catalase, superoxide dismutase, and peroxidase, along with soluble protein and soluble sugar contents in leaves and roots. Photosynthetic parameters, including net photosynthetic rate (Pn), stomatal conductance (Gs), and transpiration rate (Tr), were dramatically increased in AMF-colonized cutting seedlings. Whereas, P. occultum exhibited inhibitory effects on several growth metrics, such as shoot length, leaf and root biomass, and adventitious lateral root numbers, and decreased the contents of Nitrogen (N), potassium (K), magnesium (Mg), and iron (Fe) in both leaves and roots. These findings conclusively demonstrate that AMF symbiosis optimizes root morphology, enhances nutrient acquisition, and boosts photosynthetic efficiency and stress resilience, thus providing valuable insights for developing targeted bio-fertilization strategies in sustainable viticulture. Full article

Verticillium longisporum, a soil-borne fungus responsible for Verticillium wilt, primarily colonizes members of the Brassicaceae family. Using Arabidopsis thaliana roots as an experimental host, we systematically identify V. longisporum-responsive genes and pathways through comprehensive transcriptomic analysis, alongside screening of potential hub genes and evaluation of infection-associated regulatory mechanisms. The GSE62537 dataset was retrieved from the Gene Expression Omnibus database. After performing GEO2R analysis and filtering out low-quality data, 222 differentially expressed genes (DEGs) were identified, of which 184 were upregulated. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed on these DEGs. A protein–protein interaction network was constructed using the STRING database. CytoHubba and CytoNCA plugins in Cytoscape v3.10.3 were used to analyze and evaluate this network; six hub genes and four functional gene modules were identified. The GeneMANIA database was used to construct a co-expression network for hub genes. Systematic screening of transcription factors within the 14 DEGs revealed the inclusion of the hub gene NAC042. Integrative bioinformatics analysis centered on NAC042 enabled prediction of a pathogen-responsive regulatory network architecture. We report V. longisporum-responsive components in Arabidopsis, providing insights for disease resistance studies in Brassicaceae crops. Full article

Mycorrhizal symbiosis in rice enhances drought adaptation but there are limited studies regarding the frequency and amplitude of mycorrhizae colonization in traditional landraces. This study investigates mycorrhizal colonization frequency (FMS) and intensity (IRS) in 12 rice landraces across three agroecological zones (Tarai, Inner-Tarai, Mid-hill) of Far-West Nepal under drought stress. Field experiments exposed landraces to control, intermittent, and complete drought treatments, with soil properties and root colonization analyzed. Results revealed FMS and IRS variations driven by soil composition and genotype. Mid-hill soils (acidic, high organic matter) showed lower FMS but elevated IRS under drought, while neutral pH in Tarai and silt/clay-rich soils supported higher FMS. Sandy soil in Inner-Tarai also promoted FMS. Drought significantly increased IRS, particularly in Anjana and Sauthiyari (Tarai), Chiudi and Shanti (Inner-Tarai), and Chamade and Jhumke (Mid-hill), which exhibited IRS surges of 171–388%. These landraces demonstrated symbiotic resilience, linking mycorrhizal networks to enhanced nutrient/water uptake. Soil organic matter and nutrient levels amplified IRS responses, underscoring fertility’s role in adaptation. FMS ranged from 50 to 100%, and IRS 1.20–19.74%, with intensity being a stronger drought-tolerance indicator than frequency. The study highlights the conservation urgency for these landraces, as traditional varieties decline due to hybrid adoption. Their drought-inducible mycorrhizal symbiosis offers a sustainable strategy for climate-resilient rice production, emphasizing soil–genotype interactions in agroecological adaptation. Full article

Calcium-dependent protein kinases (CDPKs) are crucial regulators in calcium-mediated signal transduction pathways, playing a pivotal role in plant response to abiotic stresses. However, there is still limited knowledge regarding the genes of the Populus tomentosa CDPK family and their underlying functions in response to arsenic (As) stress and arbuscular mycorrhizal fungi (AMF) colonization. In our study, 20 PtCDPKs were identified in the P. tomentosa genome. Phylogenetic analysis categorized these PtCDPK genes into four subgroups based on sequence homology. Motif analysis revealed that PtCDPK genes within the same group share a similar exon–intron structure, conserved domains, and composition. The promoters of PtCDPK genes were found to contain a multitude of cis-acting elements, including light-response elements, phytohormone-response elements, and stress-response elements. The analysis of genes provided insights into the evolutionary dynamics and expansion of the PtCDPK gene family within P. tomentosa. The PtCDPK genes exhibited a strong collinear relationship with the CDPK genes of two model plants, namely, Arabidopsis thaliana and Oryza sativa L. Specifically, 10 gene pairs showed collinearity with Arabidopsis; in contrast, 14 gene pairs were collinear with rice. Transcriptome analysis of gene expression levels in P. tomentosa roots under both As stress and arbuscular mycorrhizal fungi (AMF) colonization conditions revealed that 20 PtCDPK genes had differential expression patterns. Under As stress, AMF inoculation led to the upregulation of 11 PtCDPK genes (PtCDPKSK5, X2, 1-3, 20-1, 24, 26-X1-1, 26-X1-2, 29-1, 29-2, 32, and 32-X1) and the downregulation of 8 PtCDPK genes, including PtCDPK1-1, 1-2, 8-X1, 10-X4, 13, 20-2, 26-X2, and 26-X3. The RT-qPCR results for 10 PtCDPK genes were consistent with the transcriptome data, indicating that AMF symbiosis plays a regulatory role in modulating the expression of PtCDPK genes in response to As stress. The principal findings of this study were that PtCDPK genes showed differential expression patterns under As stress and AMF colonization, with AMF regulating PtCDPK gene expression in response to As stress. Our study contributes to developing a deeper understanding of the function of PtCDPKs in the Ca²⁺ signaling pathway of P. tomentosa under As stress and AMF inoculation, which is pivotal for elucidating the molecular mechanisms underlying As tolerance in AMF-inoculated P. tomentosa. Full article

Industrial wastewater management remains a critical barrier to achieving Sustainable Development Goal 6 (SDG 6) in many developing countries, where regulatory frameworks exist but affordable and scalable treatment solutions are lacking. In Pakistan, the textile sector is a leading polluter, with untreated effluents routinely discharged into rivers and agricultural lands despite stringent National Environmental Quality Standards (NEQS). This study presents a pilot-scale case from Faisalabad’s Khurrianwala industrial zone, where a decentralized, nature-based bioreactor was piloted to bridge the gap between policy and practice. The system integrates four treatment stages—anaerobic digestion (AD), floating treatment wetland (FTW), constructed wetland (CW), and sand filtration (SF)—and was further intensified via nutrient amendment, aeration, and bioaugmentation with three locally isolated bacterial strains (Acinetobacter junii NT-15, Pseudomonas indoloxydans NT-38, and Rhodococcus sp. NT-39). The fully intensified configuration achieved substantial reductions in total dissolved solids (TDS) (46%), total suspended solids (TSS) (51%), chemical oxygen demand (COD) (91%), biochemical oxygen demand (BOD) (94%), nutrients, nitrogen (N), and phosphorus (P) (86%), sulfate (26%), and chloride (41%). It also removed 95% iron (Fe), 87% cadmium (Cd), 57% lead (Pb), and 50% copper (Cu) from the effluent. The bacterial inoculants persist in the system and colonize the plant roots, contributing to stable bioremediation. The treated effluent met the national environmental quality standards (NEQS) discharge limits, confirming the system’s regulatory and ecological viability. This case study demonstrates how nature-based systems, when scientifically intensified, can deliver high-performance wastewater treatment in industrial zones with limited infrastructure—offering a replicable model for sustainable, SDG-aligned pollution control in the Global South. Full article