Roots of the xerophyte host a cohort of ionizing-radiation-resistant biotechnologically-valuable bacteria.

Bacterial communities associated with roots of , exposed to arid conditions, were investigated with a combination of cultural and metataxonomic approaches. Traditional culture-based techniques were used and 32 isolates from the irradiated roots were identified as belonging to Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria phyla. Four actinobacterial strains were shown to be ionizing-radiation (IR)-resistant: sp. PT8 (4.8 kGy (kGy)), sp. PT11 (4.4 kGy), PT10 (2.9 kGy) and PT9 (2.6 kGy), based on the D dose necessary for a 90% reduction in colony forming units (CFU). Concerning the investigation of microbial communities , metataxonomic analyses of the diversity of IR-resistant microorganisms associated with irradiated roots revealed a marked dominance of Actinobacteria (46.6%) and Proteobacteria (31.5%) compared to Bacteroidetes (4.6%) and Firmicutes (3.2%). Gamma irradiation not only changed the structure of bacterial communities, but also affected their functional properties. Comparative analyses of metabolic profiles indicated the induction of several pathways related to adaptation to oxidative stress in irradiated roots, such as DNA repair, secondary metabolites synthesis, reactive oxygen species (ROS)-mitigating enzymes, is emblematic of desert-adapted plants. Until now, there is no other work that has focused on the microbial profile of irradiated roots of this xerophyte.