The dry weight of tomato seedlings grown under white light (including red, blue and green light) was significantly lower than that of seedlings grown under red and blue light. Spectral detection of growth inhibition in tissue culture indicated that the most harmful light quality was green light with a peak at 550 nm. The plant height, fresh and dry weight of marigold grown under the light of green light increased by 30% to 50% compared with plants grown under full spectrum light. Full-spectrum light-filled green light causes the plants to be short and dry, and the fresh weight is reduced. Removing green light strengthens the flowering of marigold, while supplementing green light inhibits the flowering of Dianthus and lettuce.
However, there are also reports of green light promoting growth. Kim et al. (2006) summarized the experimental results of red-blue combined light (LEDs) supplementation with green light. It was concluded that plant growth was inhibited when green light exceeded 50%, and plant growth was enhanced when the green light ratio was less than 24%. Although the dry weight of the upper part of the lettuce is increased by the green light added by the green fluorescent light on the red and blue combined light background provided by the LED, the conclusion that the addition of green light enhances the growth and produces more biomass than the cool white light is problematic: (1) The dry weight of the biomass they observe is only the dry weight of the aboveground part. If the dry weight of the underground root system is included, the result may be different; (2) the upper part of the lettuce grown under the red, blue and green lights Plants that grow significantly under cold white fluorescent lamps are likely to have the green light (24%) of the three-color lamp far less than the result of the cool white fluorescent lamp (51%), that is, the green light suppression effect of the cool white fluorescent lamp is greater than the three colors. The results of the lamp; (3) The photosynthesis rate of the plants grown under the combination of red and blue light is significantly higher than that of the plants grown under green light, supporting the previous speculation.
The green light effect is usually opposite to the red and blue light effects. Green light can reverse the opening of the pores promoted by blue light. However, treatment of seeds with a green laser can make radishes and carrots grow to twice as large as the control. A dim green pulse can accelerate the elongation of the seedlings growing in the dark, that is, promote stem elongation. Treatment of Arabidopsis thaliana seedlings with a single green light (525 nm ± 16 nm) pulse (11.1 μmol•m-2•s-1, 9 s) from the LED source resulted in a decrease in plastid transcripts and an increase in stem growth rate.
(2007) Based on the past 50 years of research on plant photobiology, the role of green light in plant development, flowering, stomatal opening, stem growth, chloroplast gene expression and plant growth regulation was discussed. The green light perception system and red, Blue light sensors harmoniously regulate plant growth and development. Note that in this review, green light (500~600nm) is extended to include the yellow portion of the spectrum (580~600nm).