TL;DR
Pronounced cultivar × treatment interactions confirmed that PGPR efficacy is modulated by host genetic background, with resistant varieties carrying pyramided Xa resistance genes showing additive responses to biological treatment.
Seed-associated microbiota are emerging as key determinants of early plant establishment and resilience, yet their functional potential in wheat remains underexplored. Here, we isolated and functionally characterized culturable bacterial endophytes from seeds of Triticum aestivum cvs. Saekeumkang, Baeggang, and Ariheuk to assess plant growth promotion and pathogen suppression. Sixteen bacterial strains, belonging to Pseudomonadota, Actinomycetota, and Bacillota, were identified using 16S rRNA gene sequencing. Functional assays revealed the high prevalence of plant growth-promoting traits, with all isolates producing indole-3-acetic acid and 56.25% exhibiting phosphate-solubilizing activity, whereas siderophore production was restricted to Pseudomonas poae WSSR12. Despite this apparent functional redundancy, in planta assays demonstrated strong strain-specific effects on seedling biomass. Neobacillus cucumis WSSR17 consistently induced the highest increase in fresh weight. In parallel, dual culture assays against multiple Fusarium pathogens revealed that only one isolate, Calidifontibacillus erzurumensis WSSR11, showed consistent antifungal activity across all tested Fusarium strains. Notably, isolates combining multiple functional traits did not always correspond to the strongest growth promotion, underscoring the importance of host-microbe compatibility and trait expression in planta. Collectively, these findings reveal a functionally diverse seed endophytic community with complementary roles in plant growth and disease suppression. We propose that rational selection and combination of complementary strains, particularly N. cucumis WSSR17 (growth promotion), C. erzurumensis WSSR11 (biocontrol), and P. poae WSSR12 (multifunctional nutrient mobilization) could enable the development of targeted, multi-strain bioinoculant strategies for wheat. This study advances our understanding of seed microbiome functionality and provides a foundation for microbiome-informed crop improvement.
BACKGROUND Fusarium crown rot (FCR), caused predominantly by Fusarium pseudograminearum, is a devastating soil-borne disease threatening global wheat production. Systematic discovery of keystone microbial taxa with biocontrol potential from the wheat microbiome remains poorly explored. This study aimed to identify core microbiome biomarkers associated with FCR resistance and functionally validate candidate biocontrol agents. RESULTS Bacterial and fungal communities across five wheat compartments (rhizosphere, root, stem, leaf, grain) were profiled under FCR challenge. Host compartment niche was the primary driver of wheat microbial community assembly. FCR infection reduced root and stem microbial α-diversity, strengthened homogeneous selection-dominated deterministic fungal assembly in stems, coincided with declined dispersal limitation in root bacterial assembly, and disrupted microbial network stability. Integrated analysis identified Bacillus ASV_2195, enriched in healthy wheat roots, as a core FCR resistance biomarker. The corresponding strain, Bacillus sp. XN303, was isolated. Whole-genome sequencing of XN303 uncovered gene clusters encoding antimicrobial compounds and plant-beneficial traits. Functionally, XN303 directly inhibited F. pseudograminearum growth by 71.64%, reduced the FCR disease index by 79.21%, and lowered pathogen density in rhizosphere soil and stems by 22.89% and 20.28%, respectively, in pot assays. In addition, XN303 demonstrated the capacity to detoxify deoxynivalenol (DON) and activate jasmonic acid-mediated defense priming in wheat. CONCLUSION Bacillus sp. XN303, identified through microbiome-guided screening, confers robust FCR protection via pathogen antagonism, DON detoxification, growth promotion, and defense priming, representing a potential candidate biocontrol agent for sustainable FCR management. © 2026 Society of Chemical Industry.
Results indicate that B. velezensis B05 has potential as a multifunctional biocontrol agent for sustainable management of soybean root rot.
BACKGROUND Modern agriculture urgently requires sustainable alternatives to synthetic chemical pesticides to mitigate crop yield losses while protecting human health and the environment. This study evaluated the biocontrol potential and plant growth-promoting (PGP) traits of three newly isolated Streptomyces strains (Strep_22, Strep_23, and Strep_24) against severe soilborne fungal pathogens affecting durum wheat (Triticum durum Desf.) and tomato (Solanum lycopersicum L.), two economically crucial crops. RESULTS In in vitro dual-culture assays, strain Strep_22, identified as Streptomyces netropsis, demonstrated the highest overall efficacy, achieving a mean fungal growth inhibition rate of 91.52% and near-complete suppression of critical pathogens such as Agroathelia rolfsii, Fusarium solani, and Sclerotinia sclerotiorum. Kinetic modelling confirmed that Strep_22 significantly reduced fungal growth rates. Based on these outstanding findings, Strep_22 was selected for in vivo glasshouse validation. Glasshouse trials demonstrated that treatments with this strain significantly reduced disease incidence and severity (such as root rot and wilt) in both wheat and tomato crops. Concurrently, Strep_22 exhibited strong PGP traits, inducing a significant increase in plant biomass, shoot height, and root development compared to untreated, infected controls. CONCLUSION The Streptomyces strain Strep_22 represents a highly promising, dual-action biocontrol agent. It effectively protects wheat and tomato crops against devastating fungal infections while simultaneously stimulating plant vegetative growth and development. Consequently, it constitutes a valuable ecological alternative for the formulation of commercial biofertilizers and biopesticides, paving the way toward sustainable agricultural systems. © 2026 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
The potential of P1 as a promising bioinoculant candidate for sustainable agriculture in the potato sector is demonstrated and the genome lacked major virulence factors and antimicrobial traits, supporting the non-pathogenic nature of the P1 strain.
Bacterial wilt caused by Ralstonia solanacearum is a destructive soil-borne disease affecting numerous crops worldwide. Although synthetic pesticides and antibiotics are commonly used for disease management, their excessive application has raised concerns regarding environmental pollution, human health risks, and the emergence of antibiotic-resistant pathogens. As a sustainable alternative, rhizosphere microorganisms have gained attention as potential biocontrol agents. In our previous study, strain JCK-8401 exhibited strong antibacterial activity against R. solanacearum. In the present study, its biocontrol potential was comprehensively characterized through analyses of physiological and biochemical traits, antagonistic activity against phytopathogens, induction of salicylic acid (SA)-mediated defense responses using Arabidopsis thaliana PR1::GUS reporter line, and in vivo suppression of tomato bacterial wilt. Based on 16S rRNA sequence analysis, JCK-8401 was identified as Streptomyces virginiae. The strain utilized diverse carbon sources and produced hydrolytic enzymes and indole-3-acetic acid. Furthermore, it exhibited antibacterial activity against various phytopathogenic bacteria and oomycetes, though it lacked antifungal activity. Both cell suspension and culture filtrate of the strain induced GUS expression, indicating activation of the SA-mediated defense pathway. In vivo assay demonstrated that seed treatment with JCK-8401 achieved 96.40% control efficacy against tomato bacterial wilt. Additionally, pretreatment with diluted culture filtrates (250-, 500-, and 1000-fold) effectively suppressed disease incidence regardless of the application method, strongly suggesting the activation of induced systemic resistance. Overall, Streptomyces virginiae JCK-8401 is a highly promising, multifunctional biocontrol agent for managing soil-borne diseases through a synergistic combination of antibiosis, bioinoculation, and the induction of host plant defense responses.