[Effects of light quality on growth, secondary metabolites, and oxidative stress tolerance of Gynura bicolor.]

: The effects of white light, red light, blue light, yellow light, red+blue light and red+blue+yellow light on the growth and quality of Gynura bicolor were investigated under the same light intensity (350±5 μmol·m-2·s-1) by using light-emitting-diodes (LEDs) which could accurately regulate light quality and light intensity. The results indicated that compared with white light, red light could significantly promote the growth of G. bicolor and induce the accumulation of dry substance and soluble sugar content, but blue light inhibited the plant growth. The content of chlorophyll significantly decreased under the colored LEDs. Although the combination of red, blue and yellow light did not increase the dry substance accumulation, it resulted in significant elevation of total phenols, flavonoids and anthocyanins. The accumulation of these reduced substances could increase the tolerance to oxidative stress and the nutrient value in G. bicolor. This study provided a theoretical basis for G. bicolor diverse production regulated by light quality.