Endophytic bacteria associated with halophyte Seidlitzia rosmarinus Ehrenb. ex Boiss. from saline soil of Uzbekistan and their plant beneficial traits

Endophytic bacteria of halophytic plants play essential roles in salt stress tolerance. Therefore, an understanding of the true nature of plant-microbe interactions under extreme conditions is essential. The current study aimed to identify cultivable endophytic bacteria associated with the roots and shoots ofSeidlitzia rosmarinusEhrenb. ex Boiss. grown in the salt-affected soil in Uzbekistan and to evaluate their plant beneficial traits related to plant growth stimulation and stress tolerance. Bacteria were isolated from the roots and the shoots ofS. rosmarinususing culture-dependent techniques and identified by the 16S rRNA gene. RFLP (Restriction Fragment Length Polymorphism) analysis was conducted to eliminate similar isolates. Results showed that the isolates from the roots ofS. rosmarinusbelonged to the generaRothia, Kocuria, Pseudomonas, Staphylococcus, PaenibacillusandBrevibacterium. The bacterial isolates from the shoots ofS. rosmarinusbelonged to the generaStaphylococcus, Rothia, Stenotrophomonas, Brevibacterium, Halomonas, Planococcus, PlanomicrobiumandPseudomonas, which differed from those of the roots. Notably,Staphylococcus, RothiaandBrevibacteriumwere detected in both roots and shoots, indicating possible migration of some species from roots to shoots. The root-associated bacteria showed higher levels of IAA (indole-3-acetic acid) synthesis compared with those isolated from the shoots, as well as the higher production of ACC (1-aminocyclopropane-1-carboxylate) deaminase. Our findings suggest that halophytic plants are valuable sources for the selection of microbes with a potential to improve plant fitness under saline soils.