Article

Okushima, Y. et al. Functional genomic analysis of the AUXIN RESPONSE FACTOR gene family members in Arabidopsis thaliana: unique and overlapping functions of ARF7 and ARF19. Plant Cell 17, 444-463

Salk Institute, لا هویا, California, United States
The Plant Cell (Impact Factor: 9.34). 03/2005; 17(2):444-63. DOI: 10.1105/tpc.104.028316
Source: PubMed

ABSTRACT

The AUXIN RESPONSE FACTOR (ARF) gene family products, together with the AUXIN/INDOLE-3-ACETIC ACID proteins, regulate auxin-mediated transcriptional activation/repression. The biological function(s) of most ARFs is poorly understood. Here, we report the identification and characterization of T-DNA insertion lines for 18 of the 23 ARF gene family members in Arabidopsis thaliana. Most of the lines fail to show an obvious growth phenotype except of the previously identified arf2/hss, arf3/ett, arf5/mp, and arf7/nph4 mutants, suggesting that there are functional redundancies among the ARF proteins. Subsequently, we generated double mutants. arf7 arf19 has a strong auxin-related phenotype not observed in the arf7 and arf19 single mutants, including severely impaired lateral root formation and abnormal gravitropism in both hypocotyl and root. Global gene expression analysis revealed that auxin-induced gene expression is severely impaired in the arf7 single and arf7 arf19 double mutants. For example, the expression of several genes, such as those encoding members of LATERAL ORGAN BOUNDARIES domain proteins and AUXIN-REGULATED GENE INVOLVED IN ORGAN SIZE, are disrupted in the double mutant. The data suggest that the ARF7 and ARF19 proteins play essential roles in auxin-mediated plant development by regulating both unique and partially overlapping sets of target genes. These observations provide molecular insight into the unique and overlapping functions of ARF gene family members in Arabidopsis.

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    • "Zhao et al. (2002) reported that IAA inducible genes such as IAA5 increased in response to CYP79B2 overexpression. However, with the exception of PIN1, there was no detectable variation in the transcript levels of the auxinregulated genes, IAA5, DFL1, LAX1, LAX3, ARF5, PID, and ATR1, in the igi1 mutants (Okushima et al. 2005). PIN1 expression levels decreased in the 25-day-old mutants. "

    Full-text · Dataset · Dec 2015
    • "In lateral root founder cells, negative regulators of auxin signaling, such as IAA14/Solitary Root (slr) (Fukaki et al., 2002), IAA3/SHY2 (Tian and Reed, 1999), IAA19/Massugu2 (MSG2) (Tatematsu et al., 2004), and IAA28 (Rogg et al., 2001), are first degraded, resulting in the activation of the developmental pathway for lateral root morphogenesis. Downstream of IAA14/SLR are ARF7 and ARF19, which are positive regulators of lateral root formation (Okushima et al., 2005;Weijers et al., 2005;Wilmoth et al., 2005). ARF7 and ARF19 in turn activate LBD16/ASL18 (Okushima et al., 2007), LBD18/ASL20 (Lee et al., 2009), and LBDL29/ASL16 (Feng et al., 2012). "
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    • "The tir1 mutant was obtained from the Arabidopsis Biological Stock Center. The slr and arf7-1 arf19-1 mutants have been described previously (Fukaki et al. 2002; Okushima et al. 2005; Copyright © 2015 The Japanese Society for Plant Cell and Molecular Biology Okushima et al. 2007). After being sterilized for 15 min with 95% ethanol, seeds were sown on a gellan gum plate ( "
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