Integrated Metabolomic and Transcriptomic Analysis Reveals Tissue-Specific Secondary Metabolic Differentiation and Indole Alkaloid Accumulation in Evodia rutaecarpa

Abstract

Simple Summary Evodia rutaecarpa (Juss.) Benth. is a classic traditional Chinese medicinal plant with significant pharmacological activities, and its dried fruits are the officially recognized medicinal part. While most existing research focuses on the fruit, the metabolic and transcriptional characteristics of non-medicinal tissues (roots, stems, leaves, and flowers) remain underexplored, which hinders the full utilization of E. rutaecarpa plant resources. To address this gap, we conducted an integrated analysis combining widely targeted metabolomics and transcriptomics to profile the metabolic and transcriptional landscapes across four tissues of E. rutaecarpa. Our results revealed pronounced tissue-specific secondary metabolic differentiation: roots specifically accumulated quinolone alkaloids and flavonoid glycosides, whereas leaves, stems, and flowers preferentially accumulated bioactive indole alkaloids (evodiamine and rutaecarpine). Notably, leaves and flowers exhibited particularly high accumulation levels of these active alkaloids, indicating their potential as alternative sources for industrial and pharmaceutical production. We further identified key candidate structural genes and regulatory gene modules associated with indole alkaloid biosynthesis. Collectively, our findings provide a systematic foundation for the comprehensive utilization of E. rutaecarpa resources and lay a solid groundwork for future metabolic engineering of bioactive indole alkaloids.