Introduction to Plant Developmental Biology

Abstract

The current picture of development of flowering plants or angiosperms is strongly colored by the strategies employed to study the twin processes of growth and differentiation in vascular plants in general. A brief historical survey shows that the early attempts to study plant development focused on the clearly ordered process of growth whereby the structural and functional organization of the plant body, beginning with the single-celled fertilized egg or the zygote, became progressively established. This led to the thesis that the fundamental phenomena embodied in plant development are the production of specialized cells and their organization into tissues and organs of the adult plant. In this scenario, the study of meristems, most importantly of the shoot apical and root apical meristems-first organized during embryogenesis as the apicobasal body plan takes shape-became a matter of great importance, because most plant organs can be traced to the cells formed at the apical meristems. At the same time, our thinking about the development of plants appeared to center on the coordination of the dynamic activities of the root, stem, leaves, and flowers. Of course, the fact that, unlike animals, plants cannot move from place to place to find mates or seek food introduced a new idea that some fine-tuning of their growth and development occurs as a result of the prevailing environmental conditions. Little attention was given in these investigations to the determination of what processes are involved in the production of plant organs, how the processes are related, and how they are controlled.