Monoterpenoids serve as essential components of plant essential oils and play significant roles in plant growth, development, and insect resistance. Artemisia annua, an important medicinal plant, produces abundant terpenoids. While previous research on A. annua has predominantly focused on artemisinin biosynthesis and its regulation, studies on other terpenoids in this plant have significantly lagged behind. To comprehensively investigate monoterpene biosynthesis in A. annua, we analyzed monoterpenes across its different tissues using optimized extraction and chromatographic conditions developed to enhance sensitivity and resolution in our GC-MS-based analytical method. In A. annua, 31 monoterpenoid compounds were identified. Subsequently, eight candidate monoterpene synthases (mTPS) were characterized in Escherichia coli, confirming their catalytic activity in converting geranyl pyrophosphate (GPP) into distinct monoterpene products. Subcellular localization revealed these TPSs in chloroplasts, consistent with the widely reported chloroplast localization of TPS enzymes. These enzymes were functionally defined as monoterpenoid synthases, collectively responsible for synthesizing 18 monoterpenoid metabolites. Notably, AaTPS13, AaTPS19, and AaTPS20 exhibited substantial product promiscuity. Critically, the AaTPS19 was identified as the first known terpene synthase producing 2-pinanol. These findings systematically elucidate the biosynthesis of monoterpenoids in A. annua and provide key enzymatic elements for metabolic engineering and synthetic biology applications in monoterpenoid production.

The basic leucine zipper (bZIP) transcription factors play crucial roles in plant growth and stress adaptation. However, a comprehensive genome-wide analysis of this family has been lacking in the medicinal plant Coptis chinensis. In this study, we identified 55 bZIP genes (CcbZIPs) from the C. chinensis genome and systematically classified them into 12 subfamilies through phylogenetic analysis with Arabidopsis thaliana. Notably, subfamilies L and O were absent, while two orphan genes were discovered, indicating lineage-specific evolution. Expression profiling revealed that numerous CcbZIPs respond dynamically to temperature and light stresses in a tissue-specific manner. These findings provide a foundation for understanding the regulatory roles of CcbZIPs in environmental adaptation and secondary metabolism, offering potential genetic targets for future breeding aimed at improving stress tolerance and medicinal compound production in C. chinensis.