A regulatory circuit conferring varied flowering response to cold in annual and perennial plants

Diversity in flowering regulation Annual plants flower for one season and then die, whereas perennials can flower repeatedly year after year. Hyun et al. explain how different signaling pathways control such variation in flowering. The perennial pathway requires a floral integrator limited to older shoots. The annual pathway, on the other hand, allows a photoperiodic response to incite flowering on young shoots. Solutions to challenging environments may emerge through evolution as the balance between these regulatory systems shifts. Science , this issue p. 409