Red light inhibits internode elongation, promotes lateral branching and tillering, delays flower differentiation, and increases anthocyanins, chlorophyll, and carotenoids. Red light can cause positive light motion in Arabidopsis roots. Red light has a positive effect on the resistance of plants to biotic and abiotic stresses.
Infrared red light (IR) can counteract the red light effect in many cases. A low R/IR ratio results in a decrease in photosynthetic capacity of kidney beans. In the growth chamber, the white fluorescent lamp is used as the main light source, and the far-red radiation (the emission peak of 734 nm) is supplemented with LEDs to reduce the anthocyanin, carotenoid and chlorophyll content, so that the plant fresh weight, dry weight, stem length, leaf length and leaf The width is increased. The effect of supplemental FR on growth may be due to an increase in light absorption due to increased leaf area. Arabidopsis thaliana grown under low R/FR conditions is larger and thicker than the plants grown under high R/FR, with large biomass and strong cold adaptability. Different ratios of R/FR can also alter the salt tolerance of plants.