title: Arabidopsis thaliana GH3.9 in Auxin and Jasmonate Cross Talk.
abstract: Plant growth and development are governed by an intricate web of signaling networks controlled by phytohormones, such as auxin and jasmonic acid. Auxin influences all aspects of plant growth and development, ranging from embryogenesis to root and shoot morphogenesis and organ patterning. Three major groups of auxin-responsive genes have been classified as IAA/AUX, GH3 and SAUR families. Some Group I and II GH3 proteins biochemically function in conjugating amino acids to methyl jasmonate and auxin, respectively. We recently demonstrated that GH3.9, a previously uncharacterized Group II GH3 gene family member, influences primary root growth. Whereas several GH3 family members are transcriptionally induced by auxin, GH3.9 was repressed by exogenous indole-3-acetic acid (IAA) in whole seedlings. GH3.9 promoter::GUS reporter transgenic seedlings showed expression in several tissues, and application of exogenous IAA led to a shift in promoter activity from primary roots to lateral root tips, supporting the hypothesis that GH3.9 maintains auxin homeostasis by redistribution of active auxin pools in roots. GH3.9 mutations influenced both IAA- and methyl jasmonate (MeJA)-mediated root growth inhibition. In this addendum, we expand on a possible role for GH3.9 in crosstalk between auxin and jasmonate signal transduction pathways controlling plant development.
authors.affiliation: Department of Biochemistry; Plant Science Initiative; University of Nebraska; Lincoln, Nebraska USA.
authors.forename: Sadaf
authors.initials: S
authors.lastname: Khan
authors.forename: Julie M
authors.initials: JM
authors.lastname: Stone
references.citation: Plant Cell. 2003 May;15(5):1083-94
references.pmid: 12724535
references.citation: Plant Cell. 2004 Aug;16(8):2117-27
references.pmid: 15258265
references.citation: Curr Opin Plant Biol. 2005 Oct;8(5):532-40
references.pmid: 16039901
references.citation: Plant Physiol. 2003 Nov;133(3):1367-75
references.pmid: 14551332
references.citation: Plant Physiol. 1994 Feb;104(2):439-444
references.pmid: 12232095
references.citation: Plant Physiol. 2002 Oct;130(2):887-94
references.pmid: 12376653
references.citation: Plant Cell. 2005 Feb;17(2):616-27
references.pmid: 15659623
references.citation: Plant Cell. 2005 Apr;17(4):1090-104
references.pmid: 15772288
references.citation: J Biol Chem. 2007 Mar 30;282(13):10036-10046
references.pmid: 17276977
references.citation: Ann Bot. 2005 Apr;95(5):707-35
references.pmid: 15749753
references.citation: Plant Cell Physiol. 2003 Oct;44(10):1071-80
references.pmid: 14581632
references.citation: Planta. 2007 Jun;226(1):21-34
references.pmid: 17216483
references.citation: Plant J. 2001 Jan;25(2):213-21
references.pmid: 11169197
references.citation: Plant Cell. 1993 Mar;5(3):241-51
references.pmid: 8467221
references.citation: Plant Cell. 2002 Oct;14(10):2553-63
references.pmid: 12368504
references.citation: Trends Cell Biol. 2006 Aug;16(8):397-402
references.pmid: 16815705
references.citation: Planta. 2002 Aug;215(4):549-56
references.pmid: 12172836
references.citation: Plant J. 2004 Feb;37(4):471-83
references.pmid: 14756757
references.citation: Plant Mol Biol. 2002 Jun-Jul;49(3-4):373-85
references.pmid: 12036261
references.citation: Cell. 2006 Aug 11;126(3):467-75
references.pmid: 16901781
references.citation: Plant Cell. 1990 Nov;2(11):1071-80
references.pmid: 1983791
references.citation: Plant Cell. 2002 Jun;14(6):1405-15
references.pmid: 12084835
references.citation: Ann Bot. 2007 Oct;100(4):681-97
references.pmid: 17513307
references.citation: Nat Rev Mol Cell Biol. 2006 Nov;7(11):847-59
references.pmid: 16990790