Alpine Adaptive Mechanism on Rhizosphere Microbes Recruitment of Crepis napifera (Franch.) Babc. by Multi-Omics Analysis.

Background: The accumulation of secondary metabolites in medicinal plants is often influenced by a variety of factors, and rhizosphere microorganisms typically engage in complex interactions with their host plants. Crepis napifera (Franch.) Babc., a regionally significant medicinal plant, contains a diverse array of terpenoids and demonstrates substantial potential for resource development and utilization. Methods: Transcriptome sequencing, metabolomic profiling, and 16S rRNA gene amplicon sequencing were employed to assess the transcriptional expression patterns, metabolic variations, and rhizosphere microbial community composition of C. napifera (Franch.) Babc. roots distributed across various regions. Results: A total of 3679, 8615, and 11,333 differentially expressed genes (DEGs) were identified in the pairwise comparisons between H1 vs. H2, H2 vs. H3, and H1 vs. H3, respectively. Notably, 497 DEGs were consistently detected across all three comparisons. Additionally, Weighted Gene Co-expression Network Analysis (WGCNA) revealed that the expression levels of genes within the turquoise and yellow modules exhibited a significant positive correlation with elevation. In total, 462 differentially expressed metabolites (DEMs) were identified across the same comparisons. Among these compounds, terpenoids, phenolic acids, amino acids and their derivatives, lipids, and alkaloids accounted for 62.98% of the total differential metabolite content. The accumulation patterns of DEMs varied significantly across different regions in the roots of C. napifera (Franch.) Babc. under the three altitude conditions. In response to environmental conditions and the survival strategy of C. napifera (Franch.) Babc. in alpine areas, an investigation into the rhizosphere microbial community was conducted. Four key microbial genera were identified as being correlated with terpenoid biosynthesis and plant nutritional metabolism. Specifically, Pedosphaera, Acidothermus, and Nevskia exhibited terpene biosynthesis capabilities. Additionally, Herbaspirillum, a common microorganism involved in plant nitrogen fixation, respiration, carbon metabolism, and cell wall metabolism, was also enriched in the rhizosphere of C. napifera (Franch.) Babc. These findings suggested that C. napifera (Franch.) Babc. might recruit these microorganisms to enhance its resistance to environmental stress in alpine areas. Conclusions: The accumulation of terpene in C. napifera (Franch.) Babc. across different regions was influenced by transcriptional changes. The rhizosphere microbial communities also changed during this process, showing a recruitment effect that enhances plant growth and offers potential value.