Plants and hormones: An ecophysiological view on timing and plasticity

1 This paper demonstrates the role played by plant hormones in linking environmental signals with plant responses. It concentrates on two strategies for a sessile organism as a plant to cope with changing environmental conditions: life cycle timing and phenotypic adjustment. 2 The significance of abscisic acid and gibberellins for dormancy and germination, respectively, is discussed in relation to life cycle timing. Cytokinins are presented in relation to a possible role in carbon allocation. The gaseous plant hormone ethylene is discussed in relation to its involvement in wind- and water-induced changes in shoot growth. 3 Evidence for the role played by plant hormones in developmental processes and plastic responses comes from only a very few plant species. It will be a task for ecologists to come to a more generalized understanding of the involvement of plant hormones in ecological processes by applying the existing knowledge to a much wider range of species.