Growth and alkaloid yields of Catharanthus roseus (L.) G. Don cultured under red and blue LEDs

The aim of this study was to clarify optimal light quality conditions for maximizing the production of vindoline (VDL) and catharanthine (CAT) by Catharanthus roseus (L.) G. Don. in an enclosed artificial lighting plant factory. Both VDL and CAT are biosynthetic precursors of vinblastine (VBL), an anti-neoplastic agent. Since VDL and CAT occur at very low concentrations in C. roseus, the potential for increasing their production by manipulating lighting conditions is considered very important. In the first part of the experiment, we sought to identify which of the three horticultural cultivars tested (i.e. Kermesia, Dealbata and Titan) contained the highest concentrations of VDL and CAT. The Titan cultivar contained the highest CAT concentrations and had the highest seed germination rate. In the second part of the experiment, Titan was cultured hydroponically in an environmental room under a 16L/8D photoperiod and a total photosynthetic photon flux density (PPFD) of 150 μmol m s using four different lighting treatments; red light alone (R), blue light alone (B), a mixture of red and blue light (RB, R/B light PPFD ratio was 2:1), and white light from a fluorescent lamp (FL, control). A marked increase in plant growth parameters was observed in the R treatment, but no significant changes were observed in the VDL and CAT concentrations of whole leaves among the other light quality treatments. Although there were no significant differences in VDL and CAT yields, plants in the R treatment showed the highest mean concentrations of VDL and CAT among all treatments. In conclusion, irradiation with red light alone could be used to improve biomass production and yields of VDL and CAT in C. roseus, increasing the potential application of this plant species to the production of anti-cancer agents.