Forming roots from shoot: Uncovering the genes responsible for different types of roots will transform aspects of plant agriculture

Plants continuously elaborate their form through the production of new organs, including different types of roots. A primary root emerges from a seed, and lateral roots develop postembryonically from the primary root axis. In addition, plants can generate a variety of shoot-borne roots. These are called adventitious roots (1) in dicotyledonous plants, such as tomato, or crown and brace roots (2) in monocotyledonous cereal crops, such as maize or sorghum. But the developmental mechanisms associated with shoot-borne root initiation as well as the conservation of this program with lateral and wound-induced roots are largely unknown. On page 993 of this issue, Omary et al. (3) report a conserved developmental pathway for shoot-borne roots across flowering plants and a conserved "superlocus" that regulates the initiation of specialized root types.