Blue LED light irradiation enhances L-ascorbic acid content while reducing reactive oxygen species accumulation in Chinese cabbage seedlings

Chinese cabbage is one of the most representative vegetables in Southeast Asia and a main source of L-Ascorbic acid (MA) for the human diet. In this study, we applied different light qualities (red, blue and white) supported by light-emitting diode (LED) device to enhance MA content in Chinese cabbage (Brassica rapa ssp. pekinensis) seedlings. Based on our results, blue LED light irradiation with an intensity of 125 mu mol m(-2)s(-1) increased the MA content of five-day-grown Chinese cabbage seedlings by 40% compared with white LED light irradiation. Accordingly, blue LED light irradiation induced expression of the MA biosynthetic- and recycling-related genes. Interestingly, the reactive oxygen species (ROS) content of Chinese cabbage seedlings was decreased by blue LED light irradiation. In addition, the technology improving AsA content by blue LED light irradiation was applicable to other edible vegetable sprouts as well as to Chinese cabbage sprouts. Conclusively, our report introduces a source technology for artificially improving the MA content of Chinese cabbage seedlings by applying blue LED light, which implies that application of certain types of LED light enables on-purpose cultivation of crops.