Genetic and transgenic approaches to improving crop performance

Abstract

As this volume illustrates, plant hormones play important roles in all aspects of the growth and development of plants, and in their interactions with the environment and other organisms. Many of the developmental and physiological processes regulated by plant hormones are of agronomic importance: examples that will be further explored in this chapter include the roles of gibberellins in regulating stem elongation and of ethylene in promoting fruit ripening. As a consequence of the central roles of plant hormones, plant hormone signalling has been a target of genetic modification by various selective processes, from the evolution of land plants 400 million years ago, through the adaptation of species to specific ecological niches, the domestication of crop plants by prehistoric farmers, the directed breeding of improved varieties with the advent of modern genetics 100 years ago and, most recently, the targeted modification of hormone signaling pathways in transgenic plants to improve specific agronomic traits.