Transcriptomics and Metabolomics Reveal Mechanisms Underlying the Adaptation of Lamiophlomis rotata to High Altitudes.

Lamiophlomis rotata (Benth.) Kudo is a typical alpine medicinal plant. However, the mechanism underlying its adaptation to high altitudes remains incompletely understood. In this study, we integrated transcriptome and metabolome analyses. Specifically, we used third-generation sequencing for building a reference transcriptome and second-generation sequencing for differential gene expression analysis. Our findings revealed that the activation of the hydrogen sulfide signaling pathway and the reprogramming of amino acid metabolism are probable adaptation mechanisms. Different from previous reports, the hydrogen sulfide signaling may regulate the activity of cellulose synthase in addition to enhancement of antioxidant capacity and accumulation of osmolytes. By altering the agronomic traits of plants in a cell wall remodeling-dependent manner, it enables L. rotata to adapt to alpine stress. The accumulated amino acids not only store energy-efficient organic nitrogen as precursors for the synthesis of secondary metabolites but also act as signaling molecules to activate defense responses. Additionally, we propose a potential link between the hydrogen sulfide signaling pathway and amino acid metabolism. Overall, this study systematically explores the adaptation mechanism of L. rotata to high-altitude environments, offering a novel perspective for understanding the growth, development, stress responses, and secondary metabolic processes of alpine plants.