Chitinase Activity Research Articles (Page 1)

Bacillus species suppress fungal pathogens by producing antimicrobial peptides. However, there is limited evidence of comparative effects of seed biopriming and soil drenching with Bacillus on pathogen suppression. Among six Bacillus species, B. altitudinis TM22 exhibited the highest in vitro inhibition of Fusarium oxysporum f. sp. vasinfectum (FOV) associated with Fusarium wilt of cotton. Lipopeptides (LPs) and polyketides (PKs) were extracted from the two most inhibitory strains: B. altitudinis TM22 and B. atrophaeus MCM61, where LPs from TM22 showed higher in vitro inhibition of FOV. Liquid chromatography-time-of-flight mass spectrometry (LC-TOF/MS) analysis detected iturin, fengycin, surfactin, bacillibactin, bacillomycin, bacilysin and bacillaene in TM22, whereas iturin was deficient in MCM61. TM22 produced larger amounts of hydrogen cyanide, correlating with its higher antagonistic potential. In a glasshouse experiment, TM22 and MCM61 applied via seed biopriming showed the lowest disease incidence and severity and improved plant biomass compared to soil drenching. Co-application of TM22 and MCM61 improved chlorophyll a, b, carotenoids, photosynthesis rate, RWC, and stomatal conductance. Additionally, malondialdehyde, electrolyte leakage and hydrogen peroxide levels were lower in plants treated with TM22 + MCM61 + FOV. Moreover, the activity of polyphenol oxidase (PPO), peroxidase (POD), ascorbate peroxidase (APX), catalase (CAT), superoxide dismutase (SOD), β-1,3-glucanase (GLU), phenylalanine ammonia-lyase (PAL) and chitinase (CHI) enzymes was the highest in TM22 + MCM61 + FOV-treated plants. The expression of HMGR, MPK3, GST, PAL, SOD, PPO, APX, POD and CAT genes was the highest in plants subjected to co-application of TM22 and MCM61 against FOV. Our study highlights the potential of Bacillus strains TM22 and MCM61 applied via seed biopriming and soil drenching in suppressing Fusarium wilt and enhancing biomass of cotton plants. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

In this study, the seedlings of Actinidia arguta were used as the experimental materials. Arbuscular mycorrhizal fungi (AMF), Rhizophagus irregularis, and the canker pathogen Dothiorella gregaria were inoculated. The effects of AMF on the biomass of roots, stems and leaves of Actinidia arguta, the contents of malondialdehyde (MDA), proline, and stem cellulose, as well as the activities of disease-resistant enzymes such as superoxide dismutase (SOD), catalase (CAT), polyphenol oxidase (PPO), chitinase, and polygalacturonase were determined. The results showed that the inoculation of AMF could increase the biomass of roots and stems of Actinidia arguta to enhance the tree vigor and reduce the incidence of canker disease. The inoculation of AMF could significantly reduce the MDA content in the stems and roots of Actinidia arguta infected with the disease, increase the proline content in the leaves and roots, and improve the PPO activity in roots, stems and leaves, the SOD activity in stems, and the CAT activity in leaves. In the early stage of AMF inoculation, the activities of chitinase and β-1,3-glucanase in stems and roots could be increased. It is concluded that AMF enhances the resistance of Actinidia arguta to canker disease and its disease resistance by accumulating proline, reducing the MDA content, and increasing the activities of SOD, CAT, and PPO. Bangladesh J. Bot. 54(3): 695-702, 2025 (September) Special

Enhanced virulence through genetic engineering of Beauveria bassiana blastospores by overexpression of a cuticle-degrading endochitinase.

This study examines the effects of reduced nitrogen (N) application on rice straw N depolymerization in coastal saline paddy soil to establish a scientific basis for optimizing N application strategies during straw incorporation in coastal paddy systems. A 360-day field straw bag burial experiment was conducted using four N application levels: N0 (control, without N fertilizer), N1 (225 kg N/ha), N2 (300 kg N/ha), and N3 (375 kg N/ha). The results indicated that applying 300 kg N/ha significantly (p < 0.05) increased dissolved organic N (DON) content, apr and chiA gene copies, and the activities of alkaline protease, chitinase, leucine aminopeptidase, and N-acetylglucosaminidase. In addition, the application of 300 kg N/ha enhanced the synergistic effects of alkaline protein- and chitin-degrading microbial communities. Pseudomonas, Brevundimonas, Sorangium, Cohnella, and Thermosporothrix were identified as keystone taxa predominant in straw N depolymerization. Straw N depolymerization occurred by two primary pathways: direct regulation of enzyme activity by straw properties of total carbon and electrical conductivity, and indirect influence on N hydrolase activity and DON production through modified microbial community structures. The findings suggest that an application rate of 300 kg N/ha is optimal for promoting straw N depolymerization in coastal saline paddy fields.

Osthole, a natural coumarin with fungicidal and insecticidal properties, represents a privileged scaffold for agrochemical discovery. A series of osthole derivatives featuring 1,3,4-oxadiazole, amine, quinazolinone, carbamate, or halogen substituents were synthesized and evaluated for antifungal potential. Compounds 4e and 4i strongly inhibited spore germination of Botrytis cinerea, and their IC50 values (2.6 and 2.1 μg/mL, respectively) were significantly lower than those of osthole and difenoconazole. Compounds 2, 4i, 10, and 14 inhibited mycelial growth of Alternaria solani and B. cinerea more effectively than osthole. In vivo tests indicated that 4e outperformed both osthole and hymexazol against A. solani. SAR analysis indicated that introducing an amine moiety enhanced antifungal potency. Both 4i and osthole significantly reduced Chitinase activity in the tested fungi. Cytotoxicity assays revealed low to moderate toxicity toward HaCaT cells, suggesting acceptable mammalian safety. These findings support osthole derivatives as promising fungicidal candidates and inform the design of coumarin-based agrochemicals.

From sand in the Algerian Sahara, an isolated strain of Bacillus called Bacillus sp. SRIT8 showed little chitinase activity when grown in a minimal medium supplemented with chitin (2.36 U). Using Plackett-Burman and Box-Behnken statistical plans, we could maximize chitinase synthesis, which led to a notable increase in this enzymatic activity (112 U). The purification of the resulting enzyme involved three steps: ammonium sulfate precipitation, molecular exclusion chromatography, and anion exchange chromatography. This process yielded a specific activity of 5437.14 U/mg with a purification yield of 22.44%. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis examination revealed a protein band of about 31 kDa, and optimum enzyme activity was found at pH 5 and 40 °C. Enzyme activity was boosted by Ca+2, Na+, and Mn+2 ions but was suppressed by Hg+2 ions. The purified enzyme inhibited the growth of the plant pathogen Fusarium graminearum on wheat in both in vitro tests. So, it might prevent fungal infections in wheat throughout the germination process. The enzyme was also effective as a bioinsecticide, killing up to 52% of the larvae of Sitophilus granarius Linnaeus, an insect pest of stored grain. Our chitinase's capacity to hydrolyze fungus cell walls as well as insect cuticles can be utilised as biological control agent.

Chitinases that play pivotal roles in chitin biodegradation for high-value bioconversion often adopt multimodular architectures with catalytic and binding domains connected by linkers. The linkers have been proven to possess functional roles, yet their mechanistic contributions remain poorly defined. In this study, a systematic analysis of 1242 bacterial glycoside hydrolase family 18 chitinases revealed a preferred linker length of 30-45 amino acids and an enrichment in threonine-proline (TP) motifs. Engineered Serratia marcescensSmChiC variants with controlled lengths (15-60 residues) demonstrated that a 45-residue linker (GS9) optimally enhances hydrolytic efficiency (22.4-39.8% activity increase) across α-/β-/colloidal chitins, with QCM-D confirming enhanced substrate binding/hydrolysis dynamics. Strikingly, engineered SmChiC variants with different rigidities demonstrated that the TP-linker variant outperformed the wild-type, flexible (GS9), and rigid (EK) variants, exhibiting rapid substrate association as revealed by HS-AFM. These findings highlight the critical role of linker design in optimizing chitinase function and provide a foundation for engineering enhanced glycoside hydrolases.

The cereal cyst nematode, Heterodera avena, is responsible for substantial economic losses in the global production of wheat, barley, and other cereal crops. Extracellular enzymes, particularly those from the glycoside hydrolase 18 (GH18) family, such as chitinases secreted by Trichoderma spp., play a crucial role in nematode control. However, the genome-wide analysis of Trichoderma longibrachiatum T6 (T6) GH18 family genes in controlling of H. avenae remains unexplored. Through phylogenetic analysis and bioinformatics tools, we identified and conducted a detailed analysis of 18 GH18 genes distributed across 13 chromosomes. The analysis encompassed gene structure, evolutionary development, protein characteristics, and gene expression profiles following T6 parasitism on H. avenae, as determined by RT-qPCR. Our results indicate that 18 GH18 members in T6 were clustered into three major groups (A, B, and C), which comprise seven subgroups. Each subgroup exhibits highly conserved catalytic domains, motifs, and gene structures, while the cis-acting elements demonstrate extensive responsiveness to hormones, stress-related signals, and light. These members are significantly enriched in the chitin catabolic process, extracellular region, and chitinase activity (GO functional enrichment), and they are involved in amino sugar and nucleotide sugar metabolism (KEGG pathway enrichment). Additionally, 13 members formed an interaction network, enhancing chitin degradation efficiency through synergistic effects. Interestingly, 18 members of the GH18 family genes were expressed after T6 parasitism on H. avenae cysts. Notably, GH18-3 (Group B) and GH18-16 (Group A) were significantly upregulated, with average increases of 3.21-fold and 3.10-fold, respectively, from 12 to 96 h after parasitism while compared to the control group. Meanwhile, we found that the GH18-3 and GH18-16 proteins exhibit the highest homology with key enzymes responsible for antifungal activity in T. harzianum, demonstrating dual biocontrol potential in both antifungal activity and nematode control. Overall, these results indicate that the GH18 family has undergone functional diversification during evolution, with each member assuming specific biological roles in T6 effect on nematodes. This study provides a theoretical foundation for identifying novel nematicidal genes from T6 and cultivating highly efficient biocontrol strains through transgenic engineering, which holds significant practical implications for advancing the biocontrol of plant-parasitic nematodes (PPNs).

Microbial communities play critical roles in ecosystem functioning across a wide range of environmental conditions. The physiological stress imposed by temperature, pH and resource levels can shape the structure and function of microbial communities; however, while often tested independently, factors influencing physiological stress on a community rarely occur in isolation from each other. Controlled experiments simultaneously testing multiple interactive stressors allow researchers to better assess the dynamical responses of microbial communities to rapidly changing environments. Using a full factorial, controlled experiment, we tested three hypotheses for how independent and interactive effects of abiotic stresses impact bacterial community composition, structure and function in a model system. We utilised an aquatic, pitcher plant-associated bacterial community in which microbial nutrient cycling is essential to the host plant and ecosystem. Temperature, pH and resource (food) concentration had strong independent and interactive effects on bacterial community composition, structure and function. Community functions did not respond to interactive stressors in the same way. Chitinase and protease enzymatic activities had opposite responses to temperature and pH changes, indicating that diverse functional measures are necessary for understanding the varied effects of interacting stressors. The most extreme abiotic stress combination (high temperature, lowest pH and excess food) resulted in the lowest enzyme activity and reduced species richness as compared to the other treatments. Stressful conditions, especially high temperature, strengthened correlations between community structure and function. Higher phylogenetic dispersion under abiotic extremes suggested selection for diverse taxa adapted to similar conditions through convergent evolution. These interactive effects highlight the often greater-than-additive impact of multiple stressors and demonstrate that environmental filtering and trait convergence shape microbial responses to stress.

Background/Objectives: Fusarium wilt of cotton, caused by Fusarium oxysporum f. sp. vasinfectum (FOV), is a destructive vascular disease that severely impacts cotton production. Among its variants, race 4 (FOV4) is especially aggressive, leading to early season stand losses and yield reductions. While resistant cultivars of Gossypium barbadense (pima cotton) have been developed, the molecular basis of this resistance remains unclear. This study aimed to characterize transcriptomic responses associated with FOV4 resistance in pima cotton. Methods: We conducted an in vitro infection assay using two G. barbadense cultivars with contrasting phenotypes: the highly resistant ‘DP348RF’ and the highly susceptible ‘GB1031’. Root tissues were sampled at multiple stages of infection, and RNA sequencing was performed to identify differentially expressed genes and pathways contributing to resistance. Results: Resistant plants ‘DP348RF’ showed strong induction of genes related to reactive oxygen species (ROS) metabolism, chitinase activity, and lignification compared to the susceptible cultivar. Notably, genes involved in the biosynthesis and reinforcement of the Casparian strip, a critical biochemical barrier limiting pathogen penetration into vascular tissues, were uniquely and significantly upregulated in resistant roots. These transcriptional responses suggest that fortification of cell wall barriers and enhanced antimicrobial defenses contribute to effective restriction of FOV4 colonization. Conclusions: Our findings identify a distinct molecular signature of resistance to FOV4 in pima cotton, with Casparian strip reinforcement emerging as a potential mechanism limiting vascular infection. These insights provide a foundation for breeding strategies aimed at improving Fusarium wilt resistance in cotton.

Using vacant saline-alkali land for aquaculture has the advantages of resource utilization and significant economic and ecological benefits, but there is a need to understand the impact of variable alkalinity on aquacultural species. This study investigated the impact of different alkaline stress conditions (10 and 20mmol/L) on transcription and changes in intestinal microbial communities in the oriental river prawn, Macrobrachium nipponense, over a 96-h period. Under low alkalinity conditions, pathways related to carbohydrate metabolism were activated, including glycolysis/gluconeogenesis, mannose metabolism, ascorbate and aldarate metabolism, carbohydrate binding, chitinase activity, and lysosome. Such conditions also led to an increase in the number of beneficial intestinal bacteria, such as Proteobacteria, Firmicutes, Actinobacteriota, and Acidobacteriota. However, high-alkaline conditions inhibited the fibroblast growth factor receptor signaling pathway, store-operated calcium channel activity, and MAPK signaling pathway, and significantly increased the number of pathogenic intestinal bacteria, such as Citrobacter. These results suggest that low alkalinity would promote the growth of M. nipponense by activating the glycolysis pathway and increasing the number of beneficial bacteria. By contrast, high alkalinity would inhibit their immune performance by affecting key signal transduction pathways and increasing harmful bacteria in the intestinal tract. Such insights provide a theoretical basis for the subsequent adaptive aquaculture of M. nipponense in saline-alkali areas.

Rice (Oryza sativa), particularly the japonica subspecies, is a vital global food source but often suffers from short grain length and heat sensitivity, highlighting the need for genetic improvement. This study employed CRISPR/Cas9 technology to investigate the effects of Grain Size3 (GS3) gene editing in the japonica cultivar, ‘Nipponbare’. Successful GS3 editing increased grain size across stable T3 and T4 generations. Importantly, different GS3-edited lines, even when all targeted within exon 1, resulted in varied effects on grain length and other yield components. Transcriptomic analyses revealed unique gene expression profiles for each edited line, highlighting the fact that subtle GS3 mutations trigger diverse transcriptional cascades. While common differentially expressed genes (DEGs) were enriched in ethylene signaling and chitinase activity, line-specific KEGG analyses showed distinct pathway enrichments. Crucially, the CR-L5 line exhibited significantly enhanced heat tolerance at heading stage. Under high-temperature stress, CR-L5 maintained a higher relative seed setting rate and a 15% greater grain yield than the wild type. This enhanced thermotolerance in CR-L5 correlated with differing expressions of several wax biosynthesis and chitinase-related genes. Our study provides evidence that specific gs3 mutations can confer enhanced reproductive-stage thermotolerance, offering a strategy for breeding climate-resilient japonica rice with improved grain quality and yield under stress.

The increasing global demand for agricultural production is threatened by fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith, 1797), a highly polyphagous pest. The biocontrol of this pest is beneficial over chemical control. The new Metarhizium lepidiotae (Driver & Milner) (Hypocreales: Clavicipitaceae), strain ML was isolated from Mount Heng, Hunan Province in China. The biocontrol potential of ML on FAW was evaluated through laboratory bioassays, while physiological effects were examined via histopathological assays. Enzyme activity assays were conducted to assess fungal enzyme activity levels, and the relative expression levels of fungal virulence-related genes were analyzed using RT-qPCR. This study explored that the strain ML caused a high larval mortality of 97.92% at 1 × 109 spores/ml, with an LC50 of 1.26 × 104 spores/ml. The pupal mortality was 87.5% at 1 × 108 spores/ml, with an ST50 of 8.33 d. The results showed that the high virulence was driven by elevated expression of fungal virulence-related genes and enzymes. The histopathological assays proved that the extensive hyphal invasion by ML disrupted larval tissues such as cuticle, epidermis, hemolymph, fat body, and muscles, damaging the respiratory, digestive, and excretory systems. The elevated levels of chitinase (35.82 µg/h/g), protease (3,844.02 nmol/min/g), and lipase (2,288.50 nmol/min/g) activities were synergized with the expression of M. lepidiotae elastase-like serine protease gene (MLpr1), chitinase gene (Mlchit1), secreted lipase gene (MlSecL), and lipase A gene (MlLIPA) throughout the infection. These findings provided valuable insights into the pathological mechanisms driving the high virulence of M. lepidiotae against FAW, offering potential for sustainable biocontrol.

BackgroundThe Egyptian cotton leafworm (Spodoptera littoralis) is a highly destructive, pesticide-resistant pest affecting over 80 economically important crops across the Mediterranean and African regions. While chemical insecticides offer temporary relief, their long-term use poses environmental and health risks, and resistance development reduces their effectiveness. Biological control using entomopathogenic fungi, particularly Trichoderma spp., offers a sustainable alternative. Traditionally, it is used against plant pathogens, Trichoderma harzianum, T. viride, T. asperellum, and T. longibrachiatum have also shown insecticidal potential through the production of compounds like peptaibols, gliotoxins, and chitinases, and by inducing systemic resistance in plants. However, the entomopathogenic potential of native Trichoderma isolates in Egypt remains undiscovered, and field performance is often inconsistent. This study aims to identify and evaluate native Trichoderma strains against S. littoralis and enhance their biocontrol efficacy through interspecific protoplast fusion a promising parasexual technique for strain improvement.ResultsMultilocus sequence analysis targeting the tef1-α and rpb2 genes identified the isolates as T. harzianum, T. asperellum, and T. longibrachiatum. Phylogenetic analysis clustered the isolates into three well-distinctive clades corresponding to these species. Among the tested isolates, Tricho19 (T. longibrachiatum), Tricho5 (T. asperellum), and Tricho30 (T. harzianum) demonstrated the highest extracellular chitinase activity and larval mortality in oral bioassays against S. littoralis. Interspecific protoplast fusion led to the generation of fusants with significantly enhanced chitinase production and insecticidal activity relative to their parental strains. Greenhouse assays confirmed the superior performance of fusant Fus8, which exhibited the highest larval mortality and antifeedant activity, closely approaching the efficacy of a chemical insecticide.ConclusionInterspecific protoplast fusion significantly improved the entomopathogenic performance of Trichoderma strains against S. littoralis. The enhanced activity of fusant strains, particularly Fus8, highlights the potential of this cost-effective strategy to generate improved biocontrol agents. These findings contribute to the development of sustainable pest management alternatives that can reduce reliance on chemical pesticides in agriculture.

In this study, a semirational design strategy integrating sequence and structural analyses was utilized to improve the thermostability of the highly active chitinase Chi1. Comprehensive screening for thermostability and enzymatic activity led to the identification of a beneficial mutant, D615S. Thermostability evaluations demonstrated that the half-life of the D615S mutant at 40 and 45 °C was prolonged by 3.6-fold and 24-fold, respectively, compared to that of the wild-type (WT) enzyme, while its melting temperature (Tm) was increased by 6.0 °C. Molecular dynamics (MD) simulations demonstrated that the D615S mutant significantly reduced local structural fluctuations and improved overall structural stability compared to the WT enzyme, leading to a remarkable enhancement in thermostability. Furthermore, the D615S mutant sustained the efficient enzymatic degradation of chitin powder via an integrated affinity adsorption-enzymatic catalysis approach, achieving a degradation rate of 50.3% within 120 h. Subsequent separation and purification processes yielded N-acetylglucosamine (NAG) and its dimer (NAG2) with purities exceeding 95%. These findings underscore the potential of the D615S mutant for industrial applications, particularly in the field of chitin degradation.

Chaetoglobosin D isolated from the endophytic fungus MG2 exhibited a good control to apple tree Valsa canker.

Pathogen-activated Chaetomium globosum G3 enhances iron competition and other antagonistic mechanisms to suppress maize seedling blight causal agent Fusarium verticillioides.

Tomato fruit is susceptible to decay caused by Colletotrichum gloeosporioides. An edible coating derived from essential oils loaded into a chitosan polysaccharide polymer is a sustainable delivery approach to improve coating versatility and stability for reduced reliance on synthetic fungicides to combat anthracnose incidence in tomatoes. The objective of this study was to evaluate the antifungal efficacy of nanostructured thyme essential oil incorporated into chitosan coatings [Nano-(T)-EO-CS] against Colletotrichum gloeosporioides in tomato fruits, and to investigate the underlying mechanisms contributing to its inhibitory effects. Nano-(T)-EO of (1% v/v) showed the greatest antifungal activities while achieving complete inhibition of C. gloeosporioides. At (0.8% w/v) concentration, chitosan inhibited 78% of radial mycelial growth in C. gloeosporioides. Loading Nano-(T)-EO (1% v/v) into chitosan (0.8% w/v) completely inhibited spore germination (100%). The surface electron microscopy revealed that the Nano-(T)-EO-CS coating induced significant deformation and inhibited the growth of C. gloeosporioides. Compared with the control, the Nano-(T)-EO-CS coating reduced disease incidence by 50%, whereas the commercial antifungal agent Sporekill® reduced incidence by 40% in preventively inoculated tomatoes stored at 10 °C and 85% relative humidity (RH) for 14 days after harvest, and at 18 °C for 3 days at the market shelf condition. Despite chitinase activity peaking on day 14 of cold storage, it peaked significantly on day 7 in Nano-(T)-EO-CS and Sporekill®-treated tomatoes. The Nano-(T)-EO-CS coating enhanced ferric-reducing antioxidant power and total phenol content in tomatoes for 7 and 14 d of postharvest storage. The chitosan-based edible coating loaded with thyme essential oil offers a sustainable, eco-friendly alternative to chemical fungicides for improving tomato shelf life and reducing decay.

IntroductionTo explore the changes in agronomic traits, differences in disease resistance, and related enzymatic mechanisms of tobacco grafted progeny after inoculation with root-knot nematodes (RKNs), and to elucidate their defense responses.MethodsWe used the F1 progeny of tobacco grafts ‘Banqiao B (moderately resistant rootstock) + Honghua Dajinyuan (susceptible scion)’ (BHF1) and ‘G278 (resistant rootstock)+ Honghua Dajinyuan’ (GHF1) as experimental materials, with the scion variety Honghua Dajinyuan (HD) as the control. We conducted a systematic comparison of agronomic traits, disease resistance, and enzymatic characteristics among the materials 90 days post-inoculation with RKNs.Results and discussionAgronomic traits did not differ significantly between the grafted progeny and HD. The disease index (DI) of HD and BHF1 was 74.07, indicating susceptibility (S), while GHF1 exhibited a DI of 22.22, indicating moderate resistance (MR). The Soil and Plant Analyzer Development (SPAD) value of GHF1 was significantly higher than that in HD and BHF1. Although superoxide dismutase (SOD) and catalase (CAT) activities in the leaves and roots of GHF1 were comparable to those in HD, the activities of peroxidase (POD), phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), chitinase (CHT), and β-1,3-glucanase (GLU) in the roots were significantly elevated compared to those in the other treatments. Correlation analysis revealed significant negative correlations between the DI and both the SPAD value and the activities of POD, PAL, PPO, CHT, and GLU, suggesting that increased chlorophyll content and enhanced defense-related enzyme activities contributed to the improved resistance of GHF1. GHF1 thus constitutes a valuable germplasm for nematode resistance. These findings provide a foundation for the selection, propagation, and characterization of grafted tobacco progeny and offer new strategies for breeding tobacco cultivars resistant to RKNs.

Plant Growth Promoting Rhizobacteria, PGPR, can protect plants against soil-borne diseases and abiotic stress conditions. The primary objective of this study was to evaluate the effects of different PGPRs (TF1, TF2, TF3, and TF4) on the rhizosphere microbial community of silage maize in a saline–alkaline field via Illumina MiSeq high-throughput sequencing technology. Results demonstrated that different PGPRs significantly increased the harvest density (by 21.31–45.16%), plant height (by 9.12–19.98%), stem diameter (by 30.07–45.78%), and biomass (by 33.20–65.36%) of silage maize, TF3 treatment significantly increased the fresh weight (by 32.50%), while the other treatments could increase the fresh weight but not significantly. Four microbial agents significantly reduced the contents of soil available phosphorus (AP), electrical conductivity (EC), and neutral phosphatase activity (NPA), while significantly increasing the contents of available potassium (AK), ammonium nitrogen (NH4+-N), nitrate nitrogen (NO3−-N), chitinase activity (ChtA), and urease activity (UA). Specifically, TF2 and TF3 treatments significantly decreased the soil pH value, while not for TF1 and TF4. Microbiome analysis showed that four microbial agents significantly increased the relative abundances of beneficial microorganisms, such as Arthrobacter, Blastococcus, MNDI, Chaetomidium, Alternaria, Sarocladium, Acremonium, and Clonostachys, and significantly decreased the relative abundances of Gibberella and Fusarium. Mental analysis showed that the soil bacterial community structure did not significantly correlate with soil biochemical properties, while the soil fungal community structure significantly and positively correlated with pH. Maize yield significantly and positively correlated with NH4+-N, OM, AP, EC, UA, ChtA, and NPA.