ARF7 and ARF19 Regulate Lateral Root Formation via Direct Activation of<i>LBD/ASL</i>Genes in<i>Arabidopsis</i>
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- Yoko Okushima
- Nara Institute of Science and Technology, Graduate School of Biological Sciences, Takayama 8916-5, Ikoma, Nara 630-0101, Japan
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- Hidehiro Fukaki
- Nara Institute of Science and Technology, Graduate School of Biological Sciences, Takayama 8916-5, Ikoma, Nara 630-0101, Japan
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- Makoto Onoda
- Nara Institute of Science and Technology, Graduate School of Biological Sciences, Takayama 8916-5, Ikoma, Nara 630-0101, Japan
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- Athanasios Theologis
- Plant Gene Expression Center, Albany, California 94710
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- Masao Tasaka
- Nara Institute of Science and Technology, Graduate School of Biological Sciences, Takayama 8916-5, Ikoma, Nara 630-0101, Japan
説明
<jats:title>Abstract</jats:title><jats:p>Lateral root formation in Arabidopsis thaliana is regulated by two related AUXIN RESPONSE FACTORs, ARF7 and ARF19, which are transcriptional activators of early auxin response genes. The arf7 arf19 double knockout mutant is severely impaired in lateral root formation. Target-gene analysis in arf7 arf19 transgenic plants harboring inducible forms of ARF7 and ARF19 revealed that ARF7 and ARF19 directly regulate the auxin-mediated transcription of LATERAL ORGAN BOUNDARIES-DOMAIN16/ASYMMETRIC LEAVES2-LIKE18 (LBD16/ASL18) and/or LBD29/ASL16 in roots. Overexpression of LBD16/ASL18 and LBD29/ASL16 induces lateral root formation in the absence of ARF7 and ARF19. These LBD/ASL proteins are localized in the nucleus, and dominant repression of LBD16/ASL18 activity inhibits lateral root formation and auxin-mediated gene expression, strongly suggesting that these LBD/ASLs function downstream of ARF7- and ARF19-dependent auxin signaling in lateral root formation. Our results reveal that ARFs regulate lateral root formation via direct activation of LBD/ASLs in Arabidopsis.</jats:p>
収録刊行物
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- The Plant Cell
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The Plant Cell 19 (1), 118-130, 2007-01-01
Oxford University Press (OUP)
