Abstract
Saussurea involucrata, an endangered medicinal plant, thrives in high mountain regions at altitudes ranging from 3500 to 5000 m. Being a plant that grows at high altitudes means it possesses unique physiological mechanisms and stress-responsive genes that regulate and adapt to the high-altitude environment. While many cold-resistant genes have been cloned and their mechanisms studied, the genes and molecular mechanisms involved in adaptation to hypobaric hypoxia remain largely unexplored. This study conducted transcriptomic and metabolomic analyses on the leaves of S. involucrata under normal atmosphere (101 kPa) and low pressure (60 kPa). A total of 2383 differentially expressed genes (DEGs) and 336 differentially accumulated metabolites (DAMs) were identified utilizing RNA-seq and UPLS-MS techniques. The results indicated that S. involucrata exhibits responses to hypobaric hypoxia environments by engaging in DNA repair, membrane transport, hypoxic response, reproductive processes, and various metabolic activities associated with nutrient uptake and the effective utilization of chemical components. It is worth noting that under low-pressure treatment, flavonoids are predominantly negatively regulated, whereas terpenoids are primarily positively regulated. These findings identify key genes and metabolites in S. involucrata that respond to hypobaric hypoxia treatment, providing a theoretical basis for the development of its medicinal value and for low-altitude cultivation.