The HAT2 gene, a member of the HD‐Zip gene family, isolated as an auxin inducible gene by DNA microarray screening, affects auxin response in Arabidopsis

• DOI: 10.1046/j.1365-313x.2002.01488.x
• Publication Date: 2003-03-12T22:08:24Z
• Authors: Shinichiro Sawa; Maki Ohgishi; Hideki Goda; Kanako Higuchi; Yukihisa Shimada; Shigeo Yoshida; Tomokazu Koshiba
• Keywords: Homeodomain Proteins; Leucine Zippers; 0303 health sciences; Indoleacetic Acids; Sequence Homology, Amino Acid; Transcription, Genetic; Arabidopsis Proteins; Molecular Sequence Data; Arabidopsis; Gene Expression Regulation, Developmental; Blotting, Northern; Plants, Genetically Modified; Plant Roots; Naphthaleneacetic Acids; 03 medical and health sciences; Phenotype; Plant Growth Regulators; Gene Expression Regulation, Plant; Amino Acid Sequence; Plant Shoots; Oligonucleotide Array Sequence Analysis; Signal Transduction

Summary The plant hormone, auxin, regulates many aspects of growth and development. Despite its importance, the molecular mechanisms underlying action auxin are largely unknown. To gain a more comprehensive understanding primary responses to we analyzed expression genes in Arabidopsis seedlings treated with indole‐3‐acetic acid (IAA) for 15 min. We identified single gene that is downregulated early, 29 upregulated early. Several types typical transcription factors as early genes, suggesting signals mediated by master set diverse transcriptional regulators. Of responded homeobox gene, HAT2 , was induced rapidly. Furthermore, show but not other phytohormones. analyze function plant's response generated 35S::HAT2 transgenic plants. These produced long hypocotyls, epinastic cotyledons, petioles, small leaves, which characteristic phenotypes auxin‐overproducing mutants, superroot1 (sur1) superroot2 (sur2) . On hand, plants showed reduced lateral root elongation, sensitivity compared wild‐type Together results RNA blotting biochemical analyses, these findings suggest plays opposite roles shoot tissues regulating auxin‐mediated morphogenesis.