Artemisinin-based combination therapy (ACT) forms the first line of malaria treatment. However, the yield fluctuation of artemisinin has remained an unsolved problem in meeting the global demand for ACT. This problem is mainly caused by the glandular trichome (GT)-specific biosynthesis of artemisinin in all currently used Artemisia annua cultivars. Here, we report that non-GT cells of self-pollinated inbred A. annua plants can express the artemisinin biosynthetic pathway. Gene expression analysis demonstrated the transcription of six known pathway genes in GT-free leaves and calli of inbred A. annua plants. LC-qTOF-MS/MS analysis showed that these two types of GT-free materials produce artemisinin, artemisinic acid, and arteannuin B. Detailed IR-MALDESI image profiling revealed that these three metabolites and dihydroartemisinin are localized in non-GT cells of leaves of inbred A. annua plants. Moreover, we employed all the above approaches to examine artemisinin biosynthesis in the reported A. annua glandless (gl) mutant. The resulting data demonstrated that leaves of regenerated gl plantlets biosynthesize artemisinin. Collectively, these findings not only add new knowledge leading to a revision of the current dogma of artemisinin biosynthesis in A. annua but also may expedite innovation of novel metabolic engineering approaches for high and stable production of artemisinin in the future.

FLH 13-11 FL and FLH 17-66 FL are two interspecific hybrid varieties of muscadine grape resulting from the cross of Vitis munsoniana (Simpson) ex Munson and V. rotundifolia. However, profiles of flavan-3-ols and proanthocyanidins in these two hybrids have not been characterized. Herein, we report the use of high-performance liquid chromatography-quadrupole, time-of-flight, tandem mass spectrometry (HPLC-qTOF-MS/MS) to characterize these two groups of metabolites in berries. Ripe berries collected from two consecutive cropping years were used to extract metabolites. Metabolites were ionized using the negative mode. Collision-induced dissociation was performed to fragmentize ions to obtain feature fragment profiles. Based on standards, MS features, and fragments resulted from MS/MS, four flavan-3-ol aglycones, 18 gallated or glycosylated conjugates, and eight dimeric procyanidins, were annotated from berry extracts. Of these 30 metabolites, six are new methylated flavan-3-ol gallates. Furthermore, comparative profiling analysis showed obvious effects of each cultivar on the composition these 30 metabolites, indicating that genotypes control biosynthesis. In addition, cropping seasons altered profiles of these metabolites, showing effects of growing years on metabolic composition. These data are informative to enhance the application of the two cultivars in grape and wine industries in the future.

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