Integrated Transcriptome and Proteome Analysis Provides Insights into the Mechanism of Blumea balsamifera in Response...

Drought severely restricts the growth and secondary metabolism of medicinal plants. Blumea balsamifera is a water-sensitive and economically important medicinal species, yet its molecular regulatory mechanisms in response to drought remain largely unclear, which is worthy of in-depth investigation. In this study, four-month-old B. balsamifera seedlings were subjected to three treatments; normal irrigation (CK), drought stress (DS), and rehydration recovery (RW). Leaf photosynthetic parameters, L-Borneol content, and root physiological indices were determined, and transcriptomic and proteomic analyses were integrated to explore its drought response mechanism. Under drought stress, leaf net photosynthetic rate, transpiration rate, and stomatal conductance decreased sharply, while intercellular CO₂ concentration increased; L-Borneol content showed a biphasic change, and root malondialdehyde content accumulated continuously, accompanied by significant increases in antioxidant enzyme activities and osmotic regulator contents. A total of 9917 differentially expressed genes and 736 differentially expressed proteins were identified, which were mainly enriched in phenylpropanoid biosynthesis, photosynthesis and other pathways, with photosynthesis-related genes and proteins coordinately downregulated. B. balsamifera adapts to drought stress by activating the antioxidant defense system, regulating osmotic substances, and reprogramming photosynthetic networks. The key candidate genes obtained provide important targets for drought-tolerant breeding of this species, and their reliability was verified by RT-qPCR.