Overlapping and non-redundant functions of theArabidopsisauxin response factorsMONOPTEROSandNONPHOTOTROPIC HYPOCOTYL 4

• DOI: 10.1242/dev.00925
• Publication Date: 2004-02-18T18:14:37Z
• Authors: Christian S. Hardtke; Wenzislava Ckursh...; Danielle P. Vidaurre; Sasha A. Singh; George Stamatiou; Shiv B. Tiwari; Gretchen Hagen; Tom J. Guilfoyle; Thomas Berleth
• Keywords: 0301 basic medicine; Base Sequence; DNA, Plant; Indoleacetic Acids; Arabidopsis Proteins; Arabidopsis; Gene Expression Regulation, Developmental; Genes, Plant; Plants, Genetically Modified; DNA-Binding Proteins; 03 medical and health sciences; Phenotype; Gene Expression Regulation, Plant; RNA, Plant; Two-Hybrid System Techniques; Mutation; RNA, Messenger; In Situ Hybridization; Body Patterning; Transcription Factors

Transcription factors of the auxin response factor (ARF) family have been implicated in auxin-dependent gene regulation, but little is known about functions individual ARFs plants. Here, interaction assays, expression studies and combinations multiple loss- gain-of-function mutants were used to assess roles two ARFs, NONPHOTOTROPIC HYPOCOTYL 4 (NPH4/ARF7) MONOPTEROS (MP/ARF5), Arabidopsis development. Both MP NPH4 interact strongly selectively with themselves each other, are expressed vastly overlapping domains. We show that regulatory properties both genes far more related than suggested by their single mutant phenotypes. capable controlling axis formation embryo cell expansion. Interaction plants indicated joint requirement a number responses synergistic effects associated co-overexpression genes. Finally, we demonstrate antagonistic between ARF Aux/IAA Overexpression suppresses numerous defects mutation BODENLOS (BDL)/IAA12. Together these results provide evidence for biological relevance ARF-ARF ARF-Aux/IAA an can act invariantly programmed pattern as well conditional external signals.