As its tuberous alkaloids induce valuable pharmacological effects, Pinellia ternata has considerable clinical value. However, its production currently fails to meet its demand. In vitro microtuber culture, combined with salicylic acid (SA) elicitation, may provide an effective alternative to traditional field production. In this study, an in vitro P. ternata microtuber induction system was developed and used to evaluate SA-induced elicitation of alkaloid accumulation. The quality of in vitro microtubers was assessed by total alkaloid measurement, a cytotoxicity assay, and transcriptomic analysis. With or without SA treatment, P. ternata microtuber induction was achieved within 60 d using petiole-derived explants, with a microtuber proliferation rate of approximately 17 microtubers per explant. The total alkaloid content of in vitro microtubers elicited with 100 μM SA was equivalent to that of field-grown tubers, while those not treated with SA contained lower alkaloid content. The cytotoxicity assay showed preliminary cytotoxic effects of SA-treated microtubers against the breast cancer cell line SUM159, comparable to field-grown tubers. Transcriptomic analysis revealed many differentially expressed genes (DEGs) in SA-treated in vitro microtubers. Six and twelve DEGs were annotated to the tropane, piperidine, and pyridine alkaloid pathway and the isoquinoline alkaloid pathway, respectively. RT-qPCR confirmed that the genes encoding spermidine synthase (c64642_g1), hyoscyamine (6S)-dioxygenase (c62620_g1), catechol oxidase (c61704_g3), monoamine oxidase (c65996_g3), and aspartate transaminase (c71069_g1) were significantly induced by SA. This study advances the production of P. ternata microtubers without field cultivation and provides considerable genetic information regarding SA-promoted alkaloid accumulation in P. ternata.

Seed germination with selenium (Se) is promising for producing Se-biofortified foods. Mungbean (Vigna radiata (L.) Wilczek) sprout is freshly eaten as a salad dressed with sauce, making it superior for Se biofortification. Since the Se safety range for the human body is extremely narrow, it is imperative to evaluate the genotypic responses of mungbean sprouts to Se. This study evaluated the Se enrichment capacity and interaction with flavonoids and antioxidant systems in sprouts of 20 mungbean germplasms. Selenium treatment was done by immersing mungbean seeds in 20 μM sodium selenite solution for 8 h. Afterward, the biomass, Se amounts, flavonoid (particularly vitexin and isovitexin) contents, antioxidant capacity, and key biosynthetic gene expressions were measured. Sprout Se content was 2.0–7.0 μg g⁻¹ DW among the 20 mungbean germplasms. Selenium treatment differentially affected the biomass, total flavonoid, vitexin, isovitexin, antioxidant enzyme activities, and antioxidant capacities of the mungbean germplasms. Eight germplasms showed increased biomass (p < 0.05), the highest increasing by 127%, but 13 did not phenotypically respond to Se treatment. Seven and six germplasms showed varied levels of vitexin and isovitexin increment after Se treatment, the highest measuring 2.67- and 2.87-folds for vitexin and isovitexin, respectively. Two mungbean flavonoid biosynthesis genes, chalcone synthase (VrCHS) and chalcone isomerase (VrCHI) were significantly up-regulated in the germplasms with increased vitexin and isovitexin levels (p < 0.05). Moreover, Se enrichment capacity was significantly correlated with the vitexin, isovitexin, and antioxidant capacities. In conclusion, mungbean sprouts could be a useful Se-biofortified food, but the Se enrichment capacity and nutritional response must be determined for each germplasm before commercialization.