Arabidopsis NAC1 transduces auxin signal downstream of TIR1 to promote lateral root development
Abstract
Auxin plays a key role in lateral root formation, but the signaling pathway for this process is poorly understood. We show here thatNAC1, 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.
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Footnotes
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↵3 Corresponding author.
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E-MAIL chua{at}rockvax.rockefeller.edu; FAX (212) 327-8327.
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Article and publication are at www.genesdev.org/cgi/doi/10.1101/gad.852200.
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- Received September 20, 2000.
- Accepted October 16, 2000.
- Cold Spring Harbor Laboratory Press