The TORNADO1 and TORNADO2 Genes Function in Several Patterning Processes During Early Leaf Development in Arabidopsis Thaliana

Plant Cell. 2006 Apr;18(4):852-66. doi: 10.1105/tpc.105.040568. Epub 2006 Mar 10.

Abstract

In multicellular organisms, patterning is a process that generates axes in the primary body plan, creates domains upon organ formation, and finally leads to differentiation into tissues and cell types. We identified the Arabidopsis thaliana TORNADO1 (TRN1) and TRN2 genes and their role in leaf patterning processes such as lamina venation, symmetry, and lateral growth. In trn mutants, the leaf venation network had a severely reduced complexity: incomplete loops, no tertiary or quaternary veins, and vascular islands. The leaf laminas were asymmetric and narrow because of a severely reduced cell number. We postulate that the imbalance between cell proliferation and cell differentiation and the altered auxin distribution in both trn mutants cause asymmetric leaf growth and aberrant venation patterning. TRN1 and TRN2 were epistatic to ASYMMETRIC LEAVES1 with respect to leaf asymmetry, consistent with their expression in the shoot apical meristem and leaf primordia. TRN1 codes for a large plant-specific protein with conserved domains also found in a variety of signaling proteins, whereas TRN2 encodes a transmembrane protein of the tetraspanin family whose phylogenetic tree is presented. Double mutant analysis showed that TRN1 and TRN2 act in the same pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / classification
  • Arabidopsis / genetics*
  • Arabidopsis / growth & development*
  • Arabidopsis Proteins / genetics*
  • Conserved Sequence
  • Cotyledon / anatomy & histology
  • Cotyledon / physiology
  • DNA Primers
  • Gene Expression Regulation, Developmental*
  • Genes, Plant*
  • Homeostasis
  • Indoleacetic Acids / metabolism
  • Molecular Sequence Data
  • Mutation
  • Phylogeny
  • Plant Leaves / anatomy & histology
  • Plant Leaves / growth & development*
  • Polymerase Chain Reaction

Substances

  • Arabidopsis Proteins
  • DNA Primers
  • Indoleacetic Acids