Green light control of anthocyanin production in microgreens

Modern horticultural lighting systems are implementing solid-state light sources as a supplement or alternative to sunlight or other artificial lighting systems. Many lighting systems, including those with light emitting diodes, typically ignore the contributions of green wavebands in plant development, and ultimately may affect the potential value of horticultural products produced under them. It has been shown that green light can reverse anthocyanin accumulation in Arabidopsis thaliana. The goal of this work is to test the hypothesis that green wavebands can modulate the accumulation of these valued pigments in three varieties of microgreen seedlings. The results show that while anthocyanins are induced with far-red light, green light cannot reverse, and may enhance, their accumulation under low-fluence-rate conditions, but the trend reverses in some seedlings under high-fluence rate conditions. On the other hand, blue-light-induced anthocyanin accumulation may be inhibited by the addition of green wavebands, and the effect is fluence-rate dependent and varies in sensitivity and amplitude, depending on the genotype. These trials underscore the importance of considering the inhibitory effects of green light on anthocyanin accumulation when designing lighting systems.