Management of Myzus persicae in pepper still depends largely on insecticides, but resistance limits the long-term effectiveness of chemical control. Here, we used a microbiome-guided approach to identify rhizosphere bacteria associated with aphid infestation and to evaluate their potential for aphid suppression. Pepper plants were grown in soil collected from nine field sites, and rhizosphere bacterial communities were profiled using full-length 16S rRNA gene sequencing. After excluding soils with extreme physicochemical profiles, aphid-infested plants exhibited distinct rhizosphere bacterial communities characterized by the enrichment of Massilia, Rhizobium, and Chujaibacter. To further investigate these community-level patterns, culture-dependent isolation from aphid-associated rhizosphere soils yielded five strains assigned to the genera Telluria and Massilia. Among them, Telluria sp. 100-57A consistently reduced the estimated aphid population growth rate by 36.2% and 41.5% at the 500- and 1,000-fold dilutions, respectively, compared with the negative control. This strain also induced credible avoidance of treated leaves in detached-leaf choice assays. Transcriptome analysis of pepper plants treated with strain 100-57A showed enrichment of defense-related, jasmonic acid-related, and wound-response categories during the early response period relative to the negative control. Compared with acibenzolar-S-methyl (ASM), strain 100-57A showed stronger enrichment of photosynthesis-related categories, suggesting a defense-associated transcriptional response distinct from ASM treatment. These findings support microbiome-informed strategies for identifying aphid-suppressive bacteria and highlight Telluria sp. 100-57A as a promising candidate for microbiome-based aphid management in pepper.
Jun Su Noh, Gyeongjun Cho, Jihye Jung et al.· Frontiers in Plant Science· 0 citations
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.