Metabolic composition of endophytes contributed to the effect of Brassica rapa L. in improving immunity

Abstract Background. As a medicinal plant, Brassica rapa L. contains various valuable metabolites and endophytes, and has been widely used in Northwest China. However, the detailed contributions of endophytes to the mechanisms of Brassica rapa L. improving immunity were still unknown. Previously, we isolated four endophyte fungi from Brassica rapa L.. Methods. In this study, we identified the effect of endophytes of metabolites of Brassica rapa L. and its extracts in improving immunity through triggering genes relevant to NF-kB and inflammatory pathways. Then, we performed GC-MS metabolomics to analyze the metabolic variations among these four endophytes. Results. The results showed that the metabolic compositions of PR10 significantly varied from other three endophytes. PR10 is rich in amino acids, which may affect amino acids compositions of Brassica rapa L.. And the PR10 extracts highly activated genes involved in NF-κB and inflammatory pathways, reaching a consensus with the effect of Brassica rapa L.. And the dominant metabolites of PR10 were also closely associate with various diseases, including pyruvate dehydrogenase deficiency, Heart failure and various Inflammatory diseases. Thus, Brassica rapa L. may improve the inflammatory-related diseases and immunity through its specific metabolic compositions associated with endophyte PR10. Typically, trehalose was the main metabolites that made contributions to the immune-promotion effects of PR10 and Brassica rapa L.. In conclusion, metabolites highly produced by PR10 explained the medicinal value of Brassica rapa L. in improving immunity.