The Effect of Light in Vitamin C Metabolism Regulation and Accumulation in Mung Bean (Vigna radiata) Germination

Vitamin C, as an essential vitamin for humans, has important physiological functions, such as antioxidants and enzyme cofactors. Mung bean sprouts are a good source of vitamin C and light is an essential impact factor of vitamin C content during germination. This study focused on the kinetic changes and metabolic regulation mechanism of vitamin C during mung bean sprouting under three-light treatment including constant light (24 h light/0 h dark), semi-light (12 h light/12 h dark) and constant dark (0 h light/24 h dark). Results confirmed that vitamin C content increased with the raised of light time during germination. The highest level of vitamin C, appeared on three days after constant light treatment (3-DALT), was 78 - fold higher than the initial concentration. L-ascorbic acid content on 3-DALT of mung bean sprouts was 21.4 and 29.8 times higher compared to the value on day 3 with semi -light treatment and constant dark treatment, respectively. Additionally, PMI, GME, GLDH, GalUR and DHAR expressions had strong correlations with L-ascorbic acid and vitamin C responding to light. Results indicated that light had an intimate correlation with the component and biosynthesis of vitamin C.