Multi-omics identifies regulatory hubs coordinating growth-metabolism trade-offs under nitrogen deficiency in an invasive Mikania micrantha

Aims Nitrogen availability is a critical determinant of plant invasion success, yet how invasive species respond to nitrogen deficiency remains poorly understood. This study aimed to investigate the physiological and molecular responses of the globally invasive vine Mikania micrantha to nitrogen deficiency. Methods Integrative transcriptomic and metabolomic analyses were performed on M. micrantha under nitrogen deprivation. Physiological parameters including growth, root development, photosynthetic capacity, and nitrogen accumulation were assessed. Differentially expressed genes and accumulated metabolites were identified, and multi-omics network analysis was conducted to uncover central regulatory hubs. Results Nitrogen deprivation severely suppressed growth, root development, photosynthetic capacity, and nitrogen accumulation in M. micrantha . A total of 119 differentially accumulated metabolites and 3,409 differentially expressed genes were identified. Galactose metabolism and phenolic acid biosynthesis pathways were up-regulated, while photosynthesis and nucleotide metabolism were repressed. Multi-omics network analysis revealed two central regulators: the transcription factor HHO3-like negatively controlled 3,4-dimethoxycinnamic acid accumulation and positively regulated growth and photosynthetic traits; the probable zinc transporter 10 negatively associated with verbascose accumulation and positively influenced shoot biomass. Both genes were down-regulated under nitrogen deficiency, driving accumulation of growth-inhibitory secondary metabolites. Conclusions M. micrantha exhibits a high-nitrogen-demand strategy. Nitrogen deficiency triggers a resource allocation shift from growth to stress metabolism via specific regulatory hubs, thereby constraining its invasive potential in nitrogen-poor environments.