Potential plant benefits of endophytic microorganisms associated with halophyte Glycyrrhiza glabra L.

In this study, bacteria associated with licorice (Glycyrrhiza glabra L.) were characterized through 16S rRNA gene analysis. Profiling of endophytic bacteria isolated from Glycyrrhiza glabra tissues revealed 18 isolates across the following genera: Enterobacter (4), Pantoea (3), Bacillus (2), Paenibacillus (2), Achromobacter (2), Pseudomonas (1), Escherichia (1), Klebsiella (1), Citrobacter (1), and Kosakonia (1). Furthermore, the beneficial features of bacterial isolates for plants were determined. The bacterial isolates showed the capacity to produce siderophores, hydrogen cyanide (HCN), indole-3-acetic acid (IAA), chitinase, protease, glucanase, lipase, and other enzymes. Seven bacterial isolates showed antagonistic activity against F. culmorum, F. solani, and R. solani. According to these results, licorice with antimicrobial properties may serve as a source for the selection of microorganisms that have antagonistic activity against plant fungal pathogens and may be considered potential candidates for the control of plant pathogens. The selected bacterial isolates, P. polymyxa GU1, A. xylosoxidans GU6, P. azotoformans GU7, and P. agglomerans GU18, increased root and shoot growth of licorice and were able to colonize the plant root. They can also serve as an active part of bioinoculants, improving plant growth.