Jin-Long Cui

This study investigates the spatiotemporal distribution, diversity, and biocontrol potential of culturable endophytic fungi in the healthy roots of cultivated and wild Astragalus mongholicus (CA and WA), aiming to develop a microbiome-driven strategy for sustainable root rot management. A total of 304 endophytic fungal strains were isolated from roots of CA and WA, with 61 morphologically distinct representative strains identified via ITS sequencing. These strains belonged predominantly to Ascomycota (98.36%) and included 21 genera, with Fusarium (43.28%), Paraphoma (25.25%), and Alternaria (12.46%) as dominant genera. WA exhibited higher fungal diversity and evenness than CA, with community composition varying significantly by host age and cultivation status. Among the isolates, 177 strains (53 genera) showed antagonistic activity (≥ 30% inhibition rate) against root rot pathogens (F. acuminatum, F. solani, and F. oxysporum). Notably, Penicillium chrysogenum CA4-3 exhibited 78.96% inhibition against F. solani, while Paraphoma radicina CA3-15 displayed 70.23% inhibition against F. oxysporum. Bioactive strains were concentrated in 2 to 4-year-old CA roots, with Fusarium, Paraphoma, and Alternaria being the primary contributors. Mechanistic studies revealed that these fungi inhibited pathogens via secreted metabolites (causing mycelial deformation) or niche competition. The composition of endophytic fungi in A. mongholicus roots is dynamic and influenced by host development and cultivation practices. The antifungal active strain P. chrysogenum CA4-3 and P. radicina CA3-15 may possess potential value in controlling pathogenic fungi.

Improving seed germination is one of the focuses of modern agriculture. Traditionally, external environmental factors such as temperature, moisture and light are intuitive and simple for seed germination. However, the regulation of hormones and dormancy-specific genes is relatively complex, yet precise and efficient, and is still being explored and developed. In recent years, it has been discovered that endophyte, which mutually symbiotically coexist inside seeds, are also important factors affecting seed germination. Some endophytic fungi even are determinants of plant seed germination. They play important roles in regulating seed germination through hormone production, promoting seed growth by nutrient delivery and enhancing seed resistance to stress through symbiotic genes and secondary metabolites. This has become a new direction for promoting seed germination with green, efficient and sustainable advantage. In this paper, the latest research results on the combination of endophyte and traditional factors are reviewed in order to promote a more objective and complete understanding of the factors affecting plant seed germination, and to help readers grasp the current and future development direction of the field.

The effect of endophytic fungal biotransformation on the formation of metabolic substances has become a non-negligible factor in assessing the quality of medicinal plants. However, the relevant evidences are still particularly lacking. In this study, an endophytic fungus CA3-A with biotransformation activity was screened and identified as Talaromyces coprophilus from root of Astragalus mongholicus. Its biotransformation effect on host metabolism was studied by co-culture with fungus and host root. The results showed that in addition to the significant changes in primary metabolites, secondary metabolite conversions are mainly focused on compounds such as terpenoids, phenols and flavonoids. The transformed metabolic pathways are mainly enriched in glycerophospholipid metabolism, ubiquinone and terpenoid quinones biosynthesis, and tyrosine metabolism. A total of 38 signature differential metabolites are found through multivariate statistical analysis. In addition to eleven primary metabolites including glycerides and glycerophospholipids, twenty-eight secondary metabolites distribute in terpenes, sterols, phenols, flavonoids, benzene, lipids and other classes of compounds, respectively. In conclusion, this study aims to quickly focus on the signature differentially metabolites from a large amount of information, narrow the possible range of potential transformation products, and provide help for understanding of influence of endophytes on host metabolism and the search for new natural products.

Ephedra sinica is one of the most famous Chinese medicinal plants. The insufficient supply of wild resources has led to the increased use of cultivated products. However, the related medicinal quality differs significantly. Although the influence of external environment on the quality of E. sinica has been studied, the impact of endophytic microbes on it remains vague. This study characterized differential metabolites and microbial community compositions in wild and cultivated E. sinica by combining metabolomics with microbiomics, and explored the effect of endophytes on the formation of differential metabolites further. The results showed that the difference in quality between wild and cultivated E. sinica was mainly in the productions of alkaloids, flavonoids, and terpenoids. The associated endophytes had special compositional characteristics. For instance, the distribution and abundance of dominant endophytes varied between wild and cultivated E. sinica. Several endophytes had significant or highly significant correlations with the formations of ephedrine, pseudoephedrine, d-cathinone, methcathinone, coumarin, kaempferol, rhamnetin, or phenylacetic acid. This study will deepen our understanding of the plant-endophyte interactions and provide a strategy for the quality control of E. sinica products.

Ephedra sinica is one of the most famous Chinese medicinal plants. The insufficient supply of wild resources has led to the increased use of cultivated products. However, the related medicinal quality differs significantly. Although the influence of external environment on the quality of E. sinica has been studied, the impact of endophytic microbes on it remains vague. This study characterized differential metabolites and microbial community compositions in the wild and cultivated E. sinica by combining metabolomics with microbiomics, and explored the effect of endophytes on the formation of differential metabolites further. The results showed that the difference in quality between wild and cultivated E. sinica was mainly in the productions of alkaloids, flavonoids, and terpenoids. The associated endophytes had special compositional characteristics. For instance, the distribution and abundance of dominant endophytes varied between the wild and cultivated E. sinica. Several endophytes had significant, or highly significant correlations with the formations of ephedrine, pseudoephedrine, D-cathinone, methcathinone, coumarin, kaempferol, rhamnetin, or phenylacetic acid. This study will deepen our understanding of the plant-endophyte interactions and provide a strategy for the quality control of E. sinica products.