Abiotic factors and endophytes co-regulate flavone and terpenoid glycoside metabolism in Glycyrrhiza uralensis

Abstract

Recently, endorhizospheric microbiota is realized to be able to promote the secondary metabolism in medicinal plants, but the detailed metabolic regulation metabolisms and whether the promotion is influenced by environmental factors are unclear yet. Here, the major flavonoids and endophytic bacterial communities in various Glycyrrhiza uralensis Fisch. roots collected from seven distinct places in northwest China, as well as the edaphic conditions, were characterized and analyzed. It was found that the soil moisture and temperature might modulate the secondary metabolism in G. uralensis roots partially through some endophytes. One rationally isolated endophyte Rhizobium rhizolycopersici GUH21 was proved to promote the accumulation of isoliquiritin and glycyrrhizic acid significantly in roots of the potted G. uralensis under the relatively high-level watering and low temperature. Furthermore, we did the comparative transcriptome analysis of G. uralensis seedling roots in different treatments to investigate the detailed mechanisms of the environment-endophyte-plant interactions and found that the low temperature went hand in hand with the high-level watering to activate the aglycone biosynthesis in G. uralensis, while GUH21 and the high-level watering cooperatively promoted the in planta glucosyl unit production. Our study is of significance for the development of methods to rationally promote the medicinal plant quality. Key points • Soil temperature and moisture related to isoliquiritin contents in Glycyrrhiza uralensis Fisch. • Soil temperature and moisture related to the hosts’ endophytic bacterial community structures. • The causal relation among abiotic factors—endophytes—host was proved through the pot experiment.

Transcriptome Analysis on the Quality of Epimedium koreanum in Different Soil Moisture Conditions at Harvesting Stage

“…To protect against damage from biotic and abiotic stresses, the plant synthesizes flavonoids that act as antitoxins or antioxidants [23]. Endophytic fungus (Rhizobium rhizolycopersici GUH21) has been shown to significantly enhance the accumulation of isoglycyrrhizin and glycyrrhetinic acid in the root system of Glycyrrhiza glabra under increased watering and low temperatures [24].…”

Transcriptomics and metabolomics reveal the primary and secondary metabolism changes in Glycyrrhiza uralensis with different forms of nitrogen utilization

“…However, their different effects on the physiological growth of G. uralensis were not well studied and still cannot be applied to G. uralensis production. Moreover, it was reported that inoculation of endophytic fungi in G. uralensis could improve its active ingredient content, but this technique remains in the laboratory research stage and cannot yet be stably applied to G. uralensis cultivation (Mohamad et al, 2018;Liu et al, 2023). Therefore, it is essential to seek effective measures to regulate the quality of G. uralensis during its cultivation management.…”