16S rRNA amplicon profiling of Salvadora persica -associated rhizosphere bacterial communities under saline agricultural conditions

Salvadora persica (Arak) is a facultative halophyte adapted to arid and saline environments, yet its rhizosphere microbiome remains poorly characterised. We profiled bacterial communities associated with S. persica at Arak Farm, Rabigh, Saudi Arabia, using Illumina MiSeq sequencing of the V3–V4 16S rRNA region and ASV-based analysis. Three rhizosphere composites and one adjacent bulk-soil composite were analysed. Soil_51_a and Soil_52_a were dominated by Pseudomonadota, particularly Idiomarina, Marinobacter, Marinobacterium, and Halomonas, whereas Soil_53_a was dominated by Aeribacillus and the bulk soil by Bacillus. Alpha diversity was highest in Soil_51_a and Soil_52_a, while beta-diversity analyses showed marked compositional and phylogenetic heterogeneity. Rhizosphere soils were strongly alkaline (pH 8.87–9.67), highly conductive (38,267–39,833 µS cm−1), and relatively dry (10.84-13.40% water content). These findings provide an ASV-resolved baseline for S. persica rhizosphere communities and indicate substantial sample-level heterogeneity under saline agricultural conditions, although rhizosphere and edaphic effects could not be disentangled.