Glycyrrhiza uralensis Fisch. Root-associated microbiota: the multifaceted hubs associated with environmental factors, growth status and accumulation of secondary metabolites

Abstract

Glycyrrhiza uralensis Fisch. is an important, perennial medicinal plant whose root microbiome is considered to play an important role in promoting accumulation of effective medicinal ingredients (liquiritin and glycrrhizic acid). Here, we report a comprehensive analysis of the microbial community structural composition and metabolite-plant-microbes association of G. uralensis Fisch. We collected both soil and rhizosphere samples of G. uralensis from different environmental conditions (cultivated and wild) and growth years (grown for one year and three years). Our data revealed higher species diversity in the wild group than in the cultivated group. The core rhizosphere microbiome of G. uralensis comprised 78 genera, including Bacillus, Pseudomonas, Rhizobium, some of which were potential plant beneficial microbes. Our results suggest that the growth of G. uralensis has a correlation with the root-associated microbiota assemblage. Integrated analysis among rhizosphere microbial taxa, plant gene expressions, and liquiritin and glycrrhizic acid accumulation showed that the liquiritin and glycrrhizic acid accumulation exhibited associations with the rhizosphere microbial composition at the genus level. The results provide valuable information to guide cultivation of G. uralensis, and potentially to harness the power of the root-associated microbiota to improve medicinal plant production.

Rhizosphere microbial markers (micro-markers): A new physical examination indicator for traditional Chinese medicines

“…Representative high-quality medicinal plants, medicinal plants with excessive heavy metals or medicinal plants with serious diseases and pests were selected, and more than 30 batches of samples were investigated by denaturing gradient gel electrophoresis (DGGE), random amplified polymorphic DNA (RAPD), amplified ribosomal DNA restriction analysis (ARDRA), amplified fragment length polymorphism (AFLP), terminal restriction fragment length polymorphism (T-RFLP) ( Duarte et al, 2019 , Siqueira, Sakamoto, & Rosado, 2023 , Vaneechoutte et al, 1995 ) and other technologies to establish fingerprint profiling of rhizosphere microbes and screen the common microorganisms. Then, the correlations between common rhizosphere microorganisms and characteristic traits were analyzed ( Chen et al, 2022 , Chen et al, 2022 ). In addition, some easily miscible products, such as the plants in the genus of Dendrobium ( Zuo, Zu, Liu, Song, & Yuan, 2021 ) and Ferula ( Wang, Zhang, He, & Sheng, 2018 , Wang et al, 2018 ), can also be considered to establish relevant microbial standards for identification.…”

“…Land degradation is the loss of physical, chemical, or biological properties of soil by natural or anthropogenic processes and the reduction or disappearance of important ecosystem functions ( Coban, De Deyn, & van der Ploeg, 2022 ). The continuous cultivation of many medicinal plants in the same plot can lead to deterioration of basic physical and chemical properties of soil, changes in soil microbial community structure, accumulation of autotoxic substances, slow plant growth, aggravation of soil microbial community and other problems ( Chen et al, 2022 , Chen et al, 2022 ). For example, the abundance of common soil-borne pathogens (e.g.…”

Plant-Growth Promoting Endophytic Bacteria and Their Role for Maize Acclimatation to Abiotic Stress

“…Various genera of Pseudomonas, Enterobacter, Bacillus, Klebsiella, and Burkholderia, (which are normally considered pathogenic), are also present as PGPEs, promoting plant growth and development under both normal and stress conditions [14]. In most cases, these are indirect mechanisms, such as preventing the deleterious effects of other phytopathogenic microorganisms, and this function is achieved by antibiosis, induction of systemic resistance (ISR), and competitive exclusion [13][14][15]. There are several mechanisms for plant growth stimulation by PGPEs, such as nitrogen fixation; synthesis of auxin, 1-aminocyclopropane-1-carboxylate (ACC)-deaminase, siderophores production, and phosphate solubilization, and most of them are well documented [16].…”

“…It has been proposed that stress conditions cause the recruitment of particular microbial taxa from the soil. In this sense, environmental factors, such as drought, pH, and temperature have a significant impact on the microbiota associated to roots [15]. Advantages of bacterial endophytes on plant growth include protection from competing bacteria and fungi, a constant and reliable source of nutrition, and protection from exposure to a wide range of potentially deleterious environmental conditions, such as extreme temperature and the presence of inhibitory chemicals in the soil.…”

“…On one hand, the composition of the root exudate profiles changes in different plant species, genotypes, and developmental stages. Thus, it is suggested that variations in the composition of root-associated endophytic microbial are caused by changes in root exudation [15,22]. On the other hand, endophytic bacteria also synthesize a varied array of secondary metabolites with unique chemical structures that have been exploited as biocontrol agents.…”