title: Partial loss-of-function alleles reveal a role for GNOM in auxin transport-related, post-embryonic development of Arabidopsis.
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.
authors.affiliation: ZMBP, Entwicklungsgenetik, Universität Tübingen, Auf der Morgenstelle 3, D-72076 Tuebingen, Germany.
authors.forename: Niko
authors.initials: N
authors.lastname: Geldner
authors.forename: Sandra
authors.initials: S
authors.lastname: Richter
authors.forename: Anne
authors.initials: A
authors.lastname: Vieten
authors.forename: Sebastian
authors.initials: S
authors.lastname: Marquardt
authors.forename: Ramon A
authors.initials: RA
authors.lastname: Torres-Ruiz
authors.forename: Ulrike
authors.initials: U
authors.lastname: Mayer
authors.forename: Gerd
authors.initials: G
authors.lastname: Jürgens
mesh_terms: D000483:Alleles; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001693:Biological Transport, Active; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D018522:Gravitropism / Q000235:genetics; D020662:Guanine Nucleotide Exchange Factors; D007210:Indoleacetic Acids / Q000378:metabolism; D018519:Meristem / Q000254:growth & development; D008954:Models, Biological; D009154:Mutation; D010641:Phenotype; D010937:Plant Growth Regulators / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000254:growth & development
chemical_list: D029681:Arabidopsis Proteins; C088087:GNOM protein, Arabidopsis; D020662:Guanine Nucleotide Exchange Factors; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators