DoAP2/ERF89 activated the terpene synthase gene DoPAES in Dendrobium officinale and participated in the synthesis of β-patchoulene

Dendrobium officinale Kimura et Migo is a tonic plant that has both ornamental and medicinal properties. Terpenoids are significant and diverse secondary metabolites in plants, and are one of the important natural active ingredients in D. officinale . The AP2/ERF gene family plays a major role in primary and secondary metabolism. However, the AP2 / ERF transcription factor family has not been identified in D. officinale , and it is unclear if it is involved in the regulation of terpenoid biosynthesis. This study identified a sesquiterpene synthetase- β -patchoulene synthase ( DoPAES ) using transcriptome and terpenic metabolic profile analyses. A total of 111 members of the AP2 / ERF family were identified through the whole genome of D. officinale . The tissue-specific expression and gene co-expression pattern of the DoAP2/ERF family members were analyzed. The results showed that the expression of DoPAES was highly correlated with the expression of DoAP2/ERF89 and DoAP2/ERF47 . The yeast one-hybrid (Y1H) assays and dual-luciferase experiments demonstrated that DoAP2/ERF89 and DoAP2/ERF47 could regulate the expression of DoPAES . The transcriptional regulatory effects were examined using homologous transient expression of DoAP2/ERF89 in protocorms of D. officinale . DoAP2/ERF89 positively regulated the biosynthesis of β -patchoulene. This study showed that DoAP2/ERF89 can bind to the promoter region of DoPAES to control its expression and further regulate the biosynthesis of β -patchoulene in D. officinale . These results provide new insights on the regulation of terpenoid biosynthesis.