Partial loss-of-function alleles reveal a role for GNOM in auxin transport-related, post-embryonic development of Arabidopsis

Development. 2004 Jan;131(2):389-400. doi: 10.1242/dev.00926. Epub 2003 Dec 17.

Abstract

The Arabidopsis GNOM gene encodes an ARF GDP/GTP exchange factor involved in embryonic axis formation and polar localisation of the auxin efflux regulator PIN1. To examine whether GNOM also plays a role in post-embryonic development and to clarify its involvement in auxin transport, we have characterised newly isolated weak gnom alleles as well as trans-heterozygotes of complementing strong alleles. These genotypes form a phenotypic series of GNOM activity in post-embryonic development, with auxin-related defects, especially in the maintenance of primary root meristem activity and in the initiation and organisation of lateral root primordia. Our results suggest a model for GNOM action mediating auxin transport in both embryogenesis and post-embryonic organ development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Arabidopsis / genetics*
  • Arabidopsis / growth & development*
  • Arabidopsis / metabolism
  • Arabidopsis Proteins / genetics*
  • Arabidopsis Proteins / metabolism
  • Biological Transport, Active
  • Gene Expression Regulation, Developmental
  • Gene Expression Regulation, Plant
  • Genes, Plant
  • Gravitropism / genetics
  • Guanine Nucleotide Exchange Factors*
  • Indoleacetic Acids / metabolism
  • Meristem / growth & development
  • Models, Biological
  • Mutation
  • Phenotype
  • Plant Growth Regulators / genetics*
  • Plant Growth Regulators / metabolism
  • Plant Roots / growth & development

Substances

  • Arabidopsis Proteins
  • GNOM protein, Arabidopsis
  • Guanine Nucleotide Exchange Factors
  • Indoleacetic Acids
  • Plant Growth Regulators