Plant dormancy in the perennial context.

A key feature of the perennial life style in plants is the ability to cease meristem activity and to establish a dormant state in which the meristem is rendered insensitive to growth-promoting signals for some time before it is released and can resume growth. The seasonal cycling between growth and dormancy has received little attention despite its importance for perennial behaviour. In this review, we reconsider seasonal cycles of growth and dormancy in view of a new definition of dormancy as a state within the meristem, together with recent exciting developments in the study of perennials, particularly the identification of common signalling intermediates between flowering time and growth cessation in trees.