Localization of the auxin permease AUX1 suggests two functionally distinct hormone transport pathways operate in the Arabidopsis root apex.

By R. Swarup, Jir□í Friml, A. Marchant, K. Ljung, G. Sandberg, Klaus Palme, Malcolm J. Bennett. Genes & Development, 2001

668 citations recorded by the source corpus.

Auxins represent an important class of plant hormone that regulate plant development. Plants use specialized carrier proteins to transport the auxin indole-3-acetic acid (IAA) to target tissues. To date, efflux carrier-mediated polar auxin transport has been assumed to represent the sole mode of long distance IAA movement. Localization of the auxin permease AUX1 in the Arabidopsis root apex has revealed a novel phloem-based IAA transport pathway. AUX1, asymmetrically localized to the plasma membrane of root protophloem cells, is proposed to promote the acropetal, post-phloem movement of auxin to the root apex. MS analysis shows that IAA accumulation in aux1 mutant root apices is impaired, consistent with an AUX1 phloem unloading function. AUX1 localization to columella and lateral root cap tissues of the Arabidopsis root apex reveals that the auxin permease regulates a second IAA transport pathway. Expression studies using an auxin-regulated reporter suggest that AUX1 is necessary for root gravitropism by facilitating basipetal auxin transport to distal elongation zone tissues.

Subfields: Molecular Biology, Plant Science

View Paper: https://www.semanticscholar.org/paper/9e4218718dafc001c42bd03e8ec0be095fc85080

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Molecular Biology

In Plant Science

Citations in the corpus

Auxin control of root development. (2010, background): “In addition, functional analysis of AUX1/LAX family members revealed that AUX1 is required for lateral root initiation because of its role in the basipetal auxin transport from the root tip toward the basal region through outer cell layers (lateral root cap and epidermis) (Swarup et al. 2001; De Sme”
Auxin: regulation, action, and interaction. (2005, background): “AUX1 is localized asymmetrically in the plasma membrane of certain cell files, facilitating directional auxin transport (Swarup et al., 2001, 2004).”
Regulation of Root Growth by Plant Hormones—Roles for Auxin and Gibberellin (2005, background): “Recent studies on the meristem of Arabidopsis suggest that such endogenous gradient of IAA plays an indispensable role for morphogenesis (Swarup et al., 2001; Nakajima and Benfey, 2002; Jiang and Feldman, 2003).”
Auxin-dependent regulation of lateral root positioning in the basal meristem of Arabidopsis (2007, background): “, 2005), and the basipetal transport towards this region also involves AUX1 (Swarup et al., 2001; Swarup et al., 2005).”
Dissecting Arabidopsis lateral root development. (2003, background): “Roots lacking the auxin-influx-carrier component AUX1 fail to accumulate IAA at the apex [ 19 ] and exhibit a 50% reduction in the number of LR primordia that initiate [21].”
Trichoderma virens, a Plant Beneficial Fungus, Enhances Biomass Production and Promotes Lateral Root Growth through an Auxin-Dependent Mechanism in Arabidopsis1[C][W][OA] (2009, background): “…at the AUX1 locus, which encodes an auxin influx facilitator participating in both acropetal and basipetal auxin transport at the root tip (Swarup et al., 2001). doc1 is a mutant allele of BIG, which encodes a protein important for the correct location of certain auxin transport proteins…”
Regulation of phyllotaxis by polar auxin transport (2003, methodology): “To determine the expression pattern and subcellular localization of AUX1, we performed immunofluorescent detection of a haemagglutinin-tagged version of AUX1 (referred to as HA-AUX1”
Auxin transport routes in plant development (2009, background): “Auxin transport routes during root development In the primary root, auxin is transported acropetally (see Glossary, Box 1) towards the root tip by a PIN-dependent route through the vascular parenchyma and through the phloem, with subsequent AUX1-dependent unloading into protophloem cells (Friml et a”
Ethylene Regulates Root Growth through Effects on Auxin Biosynthesis and Transport-Dependent Auxin Distribution[W] (2007, positive): “(Swarup et al., 2001; Vieten et al., 2005), and lines carrying functional proPIN1,2-PIN1,2:GFP and proAUX1-AUX1:YFP (Benkova et al., 2003; Blilou et al., 2005; Vieten et al., 2005; Abas et al., 2006).”
Ethylene Upregulates Auxin Biosynthesis in Arabidopsis Seedlings to Enhance Inhibition of Root Cell Elongation[W] (2007, positive): “Similar effects were observed employing the auxin-responsive reporter IAA2 pro : b -glucuronidase ( GUS ) (Luschnig et al., 1998; Swarup et al., 2001).”
Auxin Synthesized by the YUCCA Flavin Monooxygenases Is Essential for Embryogenesis and Leaf Formation in Arabidopsis[W] (2007, background): “The AUX1 family proteins have been shown to be influx carriers (Bennett et al., 1996; Swarup et al., 2001; Yang et al., 2006).”