A novel two-component hybrid molecule regulates vascular morphogenesis of the Arabidopsis root (original) (raw)

  1. Ari Pekka Mähönen1,
  2. Martin Bonke1,
  3. Leila Kauppinen1,
  4. Marjukka Riikonen1,
  5. Philip N. Benfey2, and
  6. Ykä Helariutta1,3
  7. 1Plant Molecular Biology Laboratory, Institute of Biotechnology, POB 56, FIN-00014 University of Helsinki, Finland;2Department of Biology, New York University, New York, New York 10003, USA

Abstract

The developmental ontogeny of the vascular system (consisting of xylem, phloem and [pro]cambium) is poorly understood despite its central role in plant physiology. We show that in the_Arabidopsis_ root meristem, xylem cell lineages are specified early, whereas phloem and procambium are established through a set of asymmetric cell divisions. These divisions require the WOODEN LEG (WOL) gene. The WOL gene encodes a novel two-component signal transducer with an unusual tandem arrangement of two receiver domains. It is expressed specifically in the vasculature from the early stages of embryogenesis on, consistent with a role as a sensor for vascular morphogenesis.

Footnotes