A synergistic interaction between salt-tolerant Pseudomonas and Mesorhizobium strains improves growth and symbiotic performance of liquorice (Glycyrrhiza uralensis Fish.) under salt stress

Abstract

Chinese liquorice (Glycyrrhiza uralensis Fish.) is a salt-tolerant medicinal legume that could be utilized for bioremediation of salt-affected soils. We studied whether co-inoculation of the symbiotic Mesorhizobium sp. strain NWXJ19 or NWXJ31 with the plant growth-promoting Pseudomonas extremorientalis TSAU20 could restore growth, nodulation, and shoot/root nitrogen contents of salt-stressed G. uralensis, which was grown in potting soil and irrigated with 0, 50, and 75 mM NaCl solutions under greenhouse conditions. Irrigation with NaCl solutions clearly retarded the growth of uninoculated liquorice, and the higher the NaCl concentration (75 and 100 mM NaCl), the more adverse is the effect. The two Mesorhizobium strains, added either alone or in combination with P. extremorientalis TSAU20, responded differently to the salt levels used. The strain NWXJ19 was a good symbiont for plants irrigated with 50 mM NaCl, whereas the strain NWXJ31 was more efficient for plants irrigated with water or 75 mM NaCl solution. P. extremorientalis TSAU20 combined with single Mesorhizobium strains alleviated the salt stress of liquorice plants and improved yield and nodule numbers significantly in comparison with single-strain-inoculated liquorice. Both salt stress and inoculation raised the nitrogen content of shoots and roots. The nitrogen contents were at their highest, i.e., 30 and 35 % greater compared to non-stressed uninoculated plants, when plants were inoculated with P. extremorientalis TSAU20 and Mesorhizobium sp. NWXJ31 as well as irrigated with 75 mM NaCl solution. From this study, we conclude that dual inoculation with plant growth-promoting rhizobacteria could be a new approach to improve the tolerance of G. uralensis to salt stress, thereby improving its suitability for the remediation of saline lands.

Diversity and Antimicrobial Potential of Cultivable Endophytic Actinobacteria Associated With the Medicinal Plant Thymus roseus

“…However, the selection rationale of host plants, locations, and pretreatment methods for the isolation of endophytes is essential in biodiversity research (Strobel and Daisy, 2003;Zhang et al, 2016). Besides, endophytic resources of arid land are most likely to possess unique and diverse functions, such as degrading chitin, producing siderophore, encoding antimicrobial and antibiotic biosynthetic genes, because of their high ability to adapt the extremely arid environment (Qin et al, 2009;Cho et al, 2015;Egamberdieva et al, 2016Egamberdieva et al, , 2017cLi et al, 2018). For instance, our research group reported that the vast majority of endophytic isolates from Chinese traditional medicinal plants Ferula sinkiangensis, Glycyrrhiza uralensis, and Ferula songorica in Xinjiang arid land were capable of producing both antifungal and plant growth-promoting traits (Liu et al, 2016(Liu et al, , 2017Li et al, 2018).…”

Silicon alleviates salt and drought stress of Glycyrrhiza uralensis plants by improving photosynthesis and water status

“…is a very popular herbal plant widely appreciated as Chinese medicine. Moreover, it is commonly used as additives in tobacco and food worldwide (Egamberdieva et al 2016). It is also very important for wind hampering, sand fixing, and soil formation in arid and semiarid regions (Li and Wang 2002).…”

Biochar-based Bradyrhizobium inoculum improves growth of lupin (Lupinus angustifolius L.) under drought stress

“…Other reasons are an insufficient number of viable effective bacteria in the rhizosphere that will induce early nodulation under drought [11]. Salinity and drought were previously reported to inhibit the colonization of rhizobia in the rhizosphere of leguminous plants [12,13]. The survival of the rhizobia and the colonization of the plant root are critical for forming nodules and for causing significant effects on plant growth in hostile environments [14].…”