The effects of blue (BL) and green light (GL) treatment during the dark period were examined in Camellia sinensis as a first step to understanding the spectral effects of artificial BL and GL on plant secondary metabolism and light signaling interactions. BL could induce the expression of CRY2/3, SPAs, HY5, and R2R3-MYBs to promote the accumulation of anthocyanins and catechins in tea plants. GL, on the other hand, could stimulate the accumulation of several functional substances (e.g., procyanidin B2/B3 and l-ascorbate) and temper these BL responses via down-regulation of CRY2/3 and PHOT2. Furthermore, the molecular events that triggered by BL and GL signals were partly overlapped with abiotic/biotic stress responses. We indicate the possibility of a targeted use of BL and GL to regulate the amount of functional metabolites to enhance tea quality and taste, and to potentially trigger defense mechanisms of tea plants.
Keywords: Camellia sinensis; abiotic and biotic stress; light quality; weighted gene coexpression network; widely targeted metabolomics.