Abstract
BACKGROUND: Dendrobium nobile Lindl belongs to the genus Dendrobium of the orchid family and is a valuable herbal medicine. Drought stress severely affects the growth of D. nobile Lindl; however, the specific regulatory mechanisms have not yet been elucidated. RESULTS: In the present study, we conducted a combined transcriptome and metabolome analysis of D. nobile Lindl stems under different drought stress conditions. Global transcriptomic changes were detected in Dendrobium under different drought stress conditions. KEGG enrichment analysis showed that the DEGs were enriched in plant hormone signal transduction; cutin, suberin, and wax biosynthesis; starch and sucrose metabolism; and the biosynthesis of various plant secondary metabolites. The differentially abundant metabolites (DAMs) detected using STEM analysis were enriched in pathways associated with glucosinolate biosynthesis and cyanoamino acid metabolism. We constructed a regulatory network for the drought tolerance of Dendrobium by weighted gene co-expression analysis. CONCLUSIONS: The results showed that arginine and proline metabolism, glucosinolate biosynthesis and tyrosine metabolism pathways participated in regulating drought stress in D. nobile Lindl. Our study provides a theoretical basis for studying the drought resistance mechanisms in Dendrobium.