Arabidopsis NAC1 transduces auxin signal downstream of TIR1 to promote lateral root development.
Auxin plays a key role in lateral root formation, but the signaling pathway for this process is poorly understood. We show here that NAC1, a new member of the NAC family, is induced by auxin and mediates auxin signaling to promote lateral root development. NAC1 is a transcription activator consisting of an N-terminal conserved NAC-domain that binds to DNA and a C-terminal activation domain. This factor activates the expression of two downstream auxin-responsive genes, DBP and AIR3. Transgenic plants expressing sense or antisense NAC1 cDNA show an increase or reduction of lateral roots, respectively. Finally, TIR1-induced lateral root development is blocked by expression of antisense NAC1 cDNA, and NAC1 overexpression can restore lateral root formation in the auxin-response mutant tir1, indicating that NAC1 acts downstream of TIR1.
Xie
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Laboratory of Plant Cell Biology, Institute of Molecular Agrobiology, National University of Singapore, 117604 Singapore.
Frugis
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Colgan
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Chua
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D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins; D001483:Base Sequence; D018548:Cotyledon / Q000378:metabolism; D018076:DNA, Complementary; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D019281:Dimerization; D015870:Gene Expression; D007210:Indoleacetic Acids / Q000378:metabolism*; D008969:Molecular Sequence Data; D016376:Oligonucleotides, Antisense; D010453:Peptide Synthases / Q000378:metabolism*; D018515:Plant Leaves / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D018517:Plant Roots / Q000254:growth & development; D030821:Plants, Genetically Modified; D017434:Protein Structure, Tertiary; D020218:Response Elements; D044843:SKP Cullin F-Box Protein Ligases; D015398:Signal Transduction / Q000502:physiology*; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D015533:Transcriptional Activation
D029681:Arabidopsis Proteins; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D007210:Indoleacetic Acids; C418004:NAC1 protein, Arabidopsis; D016376:Oligonucleotides, Antisense; D010940:Plant Proteins; D015534:Trans-Activators; D044843:SKP Cullin F-Box Protein Ligases; D010453:Peptide Synthases