Effects of ultraviolet a supplemented with red light irradiation on vinblastine production in catharanthus roseus

Abstract

We investigated whether it is possible to produce vinblastine by irradiation of blue light (B, 440 nm) and ultraviolet A light (UVA, 370 nm) to Catharanthus roseus for domestic production of vinblastine using an environmentally controlled room with artificial lighting, such as a plant factory. Catharanthus roseus plants were cultivated under red light (R, 660 nm) for 28 d and then were cultivated under 3 light quality treatments: UVA supplemented with R, B, or R for 7 d. At 3 d after treatments, vinblastine content in the leaves increased sharply under UVA supplemented with R compared with R alone. The vinblastine content under B was 1/6 of that under UVA supplemented with R. Vinblastine content increased as the UVA intensity was increased from 0 to 10 Wm-2. UVA irradiation to the leaf discs made from the younger leaves raised the vinblastine content in the leaf discs more than those from the aged leaves. Therefore, UVA light should be irradiated to the young plants at early vegetable stage. For the domestic production of vinblastine, we proposed that the cultivation method of irradiating young plants with 10 Wm-2 UVA for more than 3 d.