16S rRNA Gene Amplicon Sequencing and Functional Profiling of Rhizosphere Bacteria in Date Palms Reveal Diverse...

The rhizosphere of date palm trees serves as a reservoir for plant growth-promoting bacteria (PGPB). To characterize the microbial communities and associated PGP traits within these rhizospheres, Illumina amplicon sequencing of 16S rRNA genes and Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) analysis were conducted on samples from four cultivars (Ajwa, Helwa, Rabeaa, and Ruthana) collected in Madinah, Saudi Arabia. Proteobacteria were the dominant bacterial group in most samples, except for Rabeaa, where Actinobacteria were more prevalent. The unclassified PAC002137_g genus was most abundant overall. A diverse array of PGPB genera, including Bacillus, Arthrobacter, Lysobacter, Paenibacillus, and Mesorhizobium, was identified. PICRUSt analysis revealed a plethora of potential PGP genes, with those involved in phosphate and sulfate transport, iron acquisition, and redox processes being particularly abundant. These findings suggest that the date palm rhizosphere harbors a rich microbial community capable of promoting plant growth through various mechanisms. Further investigations into the specific roles of these PGPBs could lead to the development of sustainable agricultural practices for date palm cultivation.