title: Asymmetric gibberellin signaling regulates vacuolar trafficking of PIN auxin transporters during root gravitropism.
abstract: Gravitropic bending of plant organs is mediated by an asymmetric signaling of the plant hormone auxin between the upper and lower side of the respective organ. Here, we show that also another plant hormone, gibberellic acid (GA), shows asymmetric action during gravitropic responses. Immunodetection using an antibody against GA and monitoring GA signaling output by downstream degradation of DELLA proteins revealed an asymmetric GA distribution and response with the maximum at the lower side of gravistimulated roots. Genetic or pharmacological manipulation of GA levels or response affects gravity-mediated auxin redistribution and root bending response. The higher GA levels at the lower side of the root correlate with increased amounts of PIN-FORMED2 (PIN2) auxin transporter at the plasma membrane. The observed increase in PIN2 stability is caused by a specific GA effect on trafficking of PIN proteins to lytic vacuoles that presumably occurs downstream of brefeldin A-sensitive endosomes. Our results suggest that asymmetric auxin distribution instructive for gravity-induced differential growth is consolidated by the asymmetric action of GA that stabilizes the PIN-dependent auxin stream along the lower side of gravistimulated roots.
authors: Department of Plant Cell Biology, Albrecht-von-Haller-Institute of Plant Sciences,  Georg-August University Göttingen, 37077 Göttingen,  Germany.
authors: Christian
authors: C
authors: Löfke
authors: Marta
authors: M
authors: Zwiewka
authors: Ingo
authors: I
authors: Heilmann
authors: Marc C E
authors: MC
authors: Van Montagu
authors: Thomas
authors: T
authors: Teichmann
authors: Jirí
authors: J
authors: Friml
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D020126:Brefeldin A / Q000494:pharmacology; D011992:Endosomes / Q000187:drug effects / Q000378:metabolism; D005875:Gibberellins / Q000378:metabolism* / Q000494:pharmacology; D006112:Gravitation; D018522:Gravitropism / Q000187:drug effects*; D007210:Indoleacetic Acids / Q000378:metabolism*; D018517:Plant Roots / Q000187:drug effects / Q000502:physiology*; D055550:Protein Stability / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects; D014617:Vacuoles / Q000187:drug effects / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D005875:Gibberellins; D007210:Indoleacetic Acids; D020126:Brefeldin A
references: Nature. 2005 Jun 30;435(7046):1251-6
references: 15988527
references: Science. 2006 May 12;312(5775):883
references: 16601151
references: Plant Cell. 1994 Oct;6(10):1509-18
references: 7994182
references: Proc Natl Acad Sci U S A. 2010 Dec 21;107(51):22344-9
references: 21135243
references: Plant Cell. 2004 Nov;16(11):3069-83
references: 15486104
references: Genes Dev. 2006 Oct 15;20(20):2902-11
references: 17043314
references: Development. 2008 Oct;135(20):3345-54
references: 18787070
references: Plant Physiol. 1987;83:645-51
references: 11539033
references: Nature. 2003 Nov 13;426(6963):147-53
references: 14614497
references: Plant J. 2010 Mar;61(5):883-92
references: 20003134
references: Plant Cell. 1997 Nov;9(11):1963-71
references: 9401121
references: Plant J. 2008 Jan;53(2):380-92
references: 18047472
references: Genes Dev. 1997 Dec 1;11(23):3194-205
references: 9389651
references: Curr Biol. 2010 Jun 22;20(12):1138-43
references: 20605455
references: Mech Dev. 2013 Jan;130(1):82-94
references: 22425600
references: Genes Dev. 1998 Jul 15;12(14):2175-87
references: 9679062
references: Proc Natl Acad Sci U S A. 2008 Nov 18;105(46):17812-7
references: 19004783
references: Biosci Biotechnol Biochem. 2004 Apr;68(4):952-4
references: 15118332
references: Nat Cell Biol. 2006 Mar;8(3):249-56
references: 16489343
references: J Exp Bot. 2005 May;56(415):1327-34
references: 15767322
references: Nature. 2008 Jan 24;451(7177):475-9
references: 18216856
references: Nat Protoc. 2006;1(1):104-7
references: 17406219
references: Cell. 2003 Nov 26;115(5):591-602
references: 14651850
references: Plant Cell. 1992 Feb;4(2):119-128
references: 12297643
references: Plant J. 2005 Oct;44(2):179-94
references: 16212599
references: Annu Rev Cell Dev Biol. 2008;24:447-73
references: 18837671
references: Proc Natl Acad Sci U S A. 2009 Mar 17;106(11):4284-9
references: 19246387
references: Plant Cell. 2011 Jun;23(6):2184-95
references: 21642547
references: Plant Mol Biol. 2002 Jun-Jul;49(3-4):373-85
references: 12036261
references: Proc Natl Acad Sci U S A. 2010 Jan 12;107(2):918-22
references: 20080776
references: Nat Cell Biol. 2008 May;10(5):625-8
references: 18425113
references: EMBO J. 2010 Aug 18;29(16):2700-14
references: 20717140
references: Curr Biol. 2006 Jun 6;16(11):1123-7
references: 16677815
references: Plant J. 2011 Sep;67(5):817-26
references: 21569134
references: Nature. 2001 Sep 27;413(6854):425-8
references: 11574889
references: Plant Cell. 2007 Jul;19(7):2197-212
references: 17630274
references: Plant Physiol. 1995 Jul;108(3):1049-57
references: 7630935
references: Plant Cell. 2007 Jul;19(7):2186-96
references: 17630275
references: Nature. 2002 Feb 14;415(6873):806-9
references: 11845211
references: Cell. 2010 Oct 1;143(1):111-21
references: 20887896
references: Science. 1996 Aug 16;273(5277):948-50
references: 8688077
references: Plant Cell. 2007 Jan;19(1):131-47
references: 17237354
references: Proc Natl Acad Sci U S A. 2000 Mar 28;97(7):3718-23
references: 10737809
references: Nature. 2005 Jan 6;433(7021):39-44
references: 15635403
references: Plant Cell. 2001 Jul;13(7):1555-66
references: 11449051
references: Plant J. 2003 Aug;35(4):545-55
references: 12904216
references: Nat Protoc. 2006;1(1):98-103
references: 17406218
references: Proc Natl Acad Sci U S A. 2012 Mar 20;109(12):4668-73
references: 22393022
references: Physiol Plant. 2002 Jun;115(2):175-182
references: 12060233
references: Annu Rev Plant Physiol Plant Mol Biol. 2000 Jun;51:501-531
references: 15012200
references: J Exp Bot. 2009;60(11):3075-83
references: 19436047
references: Nat Cell Biol. 2011 Apr;13(4):447-52
references: 21394084
references: Science. 2006 May 12;312(5775):914-8
references: 16601150
references: Dev Cell. 2011 Oct 18;21(4):796-804
references: 21962902
references: Physiol Plant. 2007 Sep;131(1):140-8
references: 18251932
references: EMBO J. 2013 Jan 23;32(2):260-74
references: 23211744