Wheat native endophytic bacteria isolated from Mediterranean and Atlantic agroecosystems: identification, functional profiling and seedling bioassays

Integrative functional profiling of rhizospheric and endophytic bacteria reveals Lelliottia aquatilis as a multifunctional PGPR in Himalayan ecosystems

This study introduces L. aquatilis strain MC3 as an emerging candidate for bioinoculant development and one of the first reports for identification of L. aquatilis as multifunctional PGPR from Himalayan ecosystems.

Functional Characterization of Wheat Seed Endophytic Bacteria Reveals Plant Growth-Promoting Traits and Potential Biocontrol Activity Against Fusarium Pathogens.

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.

Effects of Nature-Derived Biostimulants on Wheat Rhizosphere Microbial Biomass, Diversity, and Networks

Plant biostimulants are increasingly recognized as natural solutions that enhance plant growth and support sustainable agriculture. However, their effects on soil microbial communities remain poorly understood. This study evaluated three biostimulants: Plantiful™ (fermented marine algae with beneficial bacteria), CelexT07™ (fermented medicinal plants with beneficial bacteria), and Phylgreen™ (seaweed extract), compared with water and conventional NPK fertilization. Rhizospheric microbial biomass, community structure, and metabolic potential were assessed using metabarcoding, phospholipid fatty acid (PLFA) profiling, and Biolog EcoPlates™ assays. Total microbial biomass did not differ significantly from the untreated control. Similarly, bacterial biomass (7.4–9.8 µg/g soil) remained stable across treatments. Saprotrophic fungal biomass was 2–4-fold lower under PhylgreenTM and CelexT07TM than NPK, but comparable to the control. Bacterial and fungal communities were dominated by Actinobacteriota, Pseudomonadota, Acidobacteriota, Chloroflexota, and Ascomycota, with similar richness and diversity across treatments in wheat rhizosphere soil after 9 weeks of growth. Functional analyses revealed only modest shifts, with AWCD being significantly reduced by 43.5% under Phylgreen™ (64.11) compared with NPK (113.44), while remaining comparable to the untreated control (94.74). The network analysis results were also consistent with the previous results, indicating that biostimulant treatments maintained microbial richness. Overall, these findings support the use of the tested biostimulants as sustainable crop management tools that preserve rhizosphere microbial communities.

Endophytic and rhizospheric plant growth-promoting bacterial diversity of Avicennia marina: implications for mangrove sustainability and resilience

Uncovering the microbial diversity of Chak-hao rice: Isolation and characterisation of indigenous beneficial microbes in Manipur

Chak-hao (Oryza sativa L.), an aromatic black glutinous rice native to Manipur, is valued for its unique fragrance and high nutraceutical value, including iron, vitamin E and antioxidants. The present study aimed to isolate and characterise beneficial rhizospheric and endophytic microbes that could enhance Chak-hao rice cultivation. A total of 170 bacterial and 55 fungal isolates were obtained from different Chak-hao varieties collected from the farmers’ fields across four districts of Manipur. These isolates were screened for plant growth-promoting traits such as phosphate solubilisation, indole-3-acetic acid (IAA) production, nitrogen fixation and antagonistic activity against harmful fungal pathogens. The study showed 51.94 % phosphate solubilisation, 41.26 % produced IAA and 9.2 % exhibited nitrogen-fixing ability. Based on multiple plant growth promoting traits, 11 promising isolates were selected for molecular characterisation. The 16S ribosomal DNA (16S rDNA) sequencing identified these isolates as belonging to Bacillus, Enterobacter and Pseudomonas genera, with Bacillus species being predominant. Microbial inoculation significantly improved grain yield, straw yield and aroma-associated compounds compared to the untreated control (p ≤ 0.05, Duncan’s multiple range test). The study reveals the potential of indigenous beneficial microbes as eco-friendly biofertilisers and biocontrol agents for sustainable Chak-hao rice cultivation, quality grain improvement and conservation of unique Chak-hao rice germplasm Manipur.

Functional characterisation of endophytic bacteria of Drynaria quercifolia L.(J.)Sm: production of hydrolytic enzymes and plant growth-promotion

Endophytes are widely recognised for their ability to enhance plant growth and survival by adapting to the plant’s internal environment. The present study explores the production of hydrolytic enzymes and plant growth-promoting traits in endophytic bacteria isolated from Drynaria quercifolia. Out of the 34 endophytic bacteria isolated, fifteen morphologically distinct bacterial isolates were initially screened for their ability to produce hydrolytic enzymes and plant growth-promoting compounds. Based on their functional attributes, seven distinct isolates were selected for molecular identification using 16S rRNA gene sequencing. Sequence analysis revealed close similarity to Rothia halotolerans, two distinct strains of Agrobacterium tumefaciens, Mycolicibacterium bacteremicum, Rhizobium sp., Microbacterium sp., and Leifsonia shinshuensis. To the best of our knowledge, this is the first study documenting these particular bacterial taxa as endophytes with plant growth-promoting potential associated with D. quercifolia. Among the identified isolates, Agrobacterium tumefaciens demonstrated the most pronounced plant growth–promoting activity.