Phytochrome B1-dependent control of SP5G transcription is the basis of the night break and red to far-red light ratio effects in tomato flowering

Phytochromes are dimeric proteins with critical roles in perceiving day length and the environmental signals that trigger flowering. Night break (NB) and the red to far-red light ratio (R:FR) have been used extensively as tools to study the photoperiodic control of flowering.