Endorhizosphere of indigenous succulent halophytes: a valuable resource of plant growth promoting bacteria

Abstract

The adaptability of halophytes to increased soil salinity is related to complex rhizosphere interactions. In this study, an integrative approach, combining culture-independent and culture-dependent techniques was used to analyze the bacterial communities in the endorizosphere of indigenous succulent halophytes Salicornia europaea, Suaeda maritima, and Camphorosma annua from the natural salt marshes of Slano Kopovo (Serbia). The 16 S rDNA analyses gave, for the first time, an insight into the composition of the endophytic bacterial communities of S. maritima and C. annua. We have found that the composition of endophyte microbiomes in the same habitat is to some extent influenced by plant species. A cultivable portion of the halophyte microbiota was tested at different NaCl concentrations for the set of plant growth promoting (PGP) traits. Through the mining of indigenous halotolerant endophytes, we obtained a collection representing a core endophyte microbiome conferring desirable PGP traits. The majority (65%) of the selected strains belonged to the common halotolerant/halophilic genera Halomonas, Kushneria, and Halobacillus, with representatives exhibiting multiple PGP traits, and retaining beneficial traits in conditions of the increased salinity. The results suggest that the root endosphere of halophytes is a valuable source of PGP bacteria supporting plant growth and fitness in salt-affected soils.

Diversity, Characterization, and Potential Applications of Bacterial Endophytes Isolated from the Halophyte Limonium axillare

“…1qu (AL1) 00.0 ± 0.0 64.8 ± 1.5 57.7 ± 0.5 57.2 ± 0.2 (PGP) mechanisms involves ACC deaminase, which mitigates the impact of salt stress by reducing ethylene levels in plants (Dragojević et al 2023;Madhaiyan et al 2006;Glick 2014). While salt stress typically inhibits the synthesis of indole-3-acetic acid (IAA) in plants, endophytic bacteria can compensate by producing their own IAA, promoting the growth of plant roots, stems, and leaves (Selvakumar et al 2016;Choudhury et al 2021).…”