Integrative analysis of microbiome composition and plant beneficial characteristics of endophytic bacteria associated with Prosopis species in arid environment

Abstract

Prosopis species, well-known for their resilience in arid and saline environments, establish complex interactions with their endophytic microbiota, which play imperative roles in plant adaptation and tolerance to environmental stresses. This study aimed to isolate and characterize endophytes from different tissues of Prosopis juliflora and P. cineraria, evaluate their plant-beneficial traits, and assess microbial community composition through high-throughput 16S rRNA sequencing. Seeds of both species were collected from arid site in Sharjah, UAE, surface-sterilized, and germinated under sterile hydroponic conditions. A total of 22 endophytic strains were isolated from seeds, nodules, and stems and identified using the VITEK® 2 compact system. Among them, Pantoea spp. were the most frequently recovered, and isolates demonstrated high salt tolerance, auxin and polyamine production, and phosphate solubilization. In parallel, high throughput 16S rRNA sequencing was performed on seeds and nodules of P. juliflora and seeds and stems of P. cineraria to investigate microbial diversity and community composition. Proteobacteria, mainly Gammaproteobacteria, were dominant across all samples. P. juliflora nodules showed the highest microbial richness and diversity. Taxonomic analysis identified Pantoea and members of the Enterobacteriaceae family as the most abundant in P. juliflora. These results suggest that endophytic bacteria from P. juliflora nodules may support the plant's adaptability, stress tolerance, and invasive success. The study provides insight into plant-microbe interactions in arid environments and identifies potential endophytic candidates for bioinoculant applications in agriculture.