XVI International Botanical Congess

The simple plant hormone ethylene promotes root cell growth in the radial direction (expansion) while inhibiting root cell growth in the longitudinal direction (elongation), resulting in shorter, thicker roots. Although a number of components of the ethylene signaling pathway have been identified, the specific mechanisms by which ethylene promotes these alterations in root cell shape are unknown. As a first step in understanding the role of ethylene in root cell shape determination, a genetic screen was executed to identify root-specific ethylene insensitive (eir) mutants in Arabidopsis thaliana. The characterization of the first of these, designated leir10, will be presented.