Abstract: Metabolomics technology was employed to analyze differences in root metabolites of soybean[Glycine max (L.) Merr.] cultivar Heike 60 after inoculation with Sinorhizobium fredii HH103(hereinafter referred to as rhizobium HH103) and its mutant HH103ΔnolR. The results showed that a total of 9 907 differential metabolites were identified between samples from the rhizobium HH103 treatment and the mutant HH103ΔnolR treatment, among which the content of 4 202 metabolites was upregulated and that of 5 705 metabolites was downregulated. Lipids and lipid-like molecules, as well as phenylpropanoids and polyketides, accounted for a relatively high proportion among the differential metabolites. Malvin exhibited the largest increase in differential metabolite content after inoculation with the rhizobium, while Physalin_F showed the largest decrease. The differential metabolites were significantly enriched in pathways such as galactose metabolism, lysine biosynthesis, porphyrin metabolism, isoquinoline alkaloid biosynthesis, and propanoate metabolism. Among the differential metabolites, the content differences in flavonoid compounds were relatively significant, and the deletion of the nolR gene promoted the metabolism of flavonoid compounds in soybean.

Key words: soybean[Glycine max (L.) Merr.], rhizobium, regulator nolR, metabolomics