Plant Vegetative Development: From Seed and Embryo to Shoot and Root.

Our understanding of plant vegetative development has been progressing at an increasingly rapid pace over the past severa1 years. The 22 reviews in this Special Issue, which were invited by Brian Larkins (Editor of THE PLANT CELL), Crispin Taylor (News and Reviews Editor of THE PLANT CELL), and lan Sussex (University of California, Berkeley) and edited by Crispin Taylor, highlight the most exciting recent advances and point the way toward important future objectives. They also constitute a comprehensive assessment of the current state of the art in plant vegetative development and serve to illustrate the wonderful diversity of vegetative structures and cells. In this overview, I wouM first like to introduce the diversity that is a hallmark of plant development and to outline some of the principles that guide and influence this diversity. Following this introduction, I will briefly discuss the topics that are covered in the reviews in this issue, before turning the stage over to the reviews and their authors, who have spent their careers trying to figure out what makes a plant a plant.