Flowering response to blue light and its molecular mechanisms in Arabidopsis and horticultural plants

Using light-emitting diodes (LEDs) in plant factories and protected horticulture is expected to decrease energy costs and environmental burden. Because LEDs emit monochromatic light, detailed knowledge of plant responses to light quality is essential for efficient and appropriate utilization of LEDs in horticultural production. Timing of flowering is important in cut flower and fruit/vegetable production, and it is often affected by light quality. Red/far-red light is well known to be effective in flowering, and there is abundant knowledge about the effects of red/far-red ratio on flowering of horticultural plants as well as of the model plant Arabidopsis thaliana. However, studies have not focused on the effects of blue light on flowering. Therefore, this review describes the progress in the promotion of flowering by blue light and its molecular mechanisms in Arabidopsis and horticultural plants.