title: GNC and CGA1 modulate chlorophyll biosynthesis and glutamate synthase (GLU1/Fd-GOGAT) expression in Arabidopsis.
abstract: Chloroplast development is an important determinant of plant productivity and is controlled by environmental factors including amounts of light and nitrogen as well as internal phytohormones including cytokinins and gibberellins (GA). The paralog GATA transcription factors GNC and CGA1/GNL up-regulated by light, nitrogen and cytokinin while also being repressed by GA signaling. Modifying the expression of these genes has previously been shown to influence chlorophyll content in Arabidopsis while also altering aspects of germination, elongation growth and flowering time. In this work, we also use transgenic lines to demonstrate that GNC and CGA1 exhibit a partially redundant control over chlorophyll biosynthesis. We provide novel evidence that GNC and CGA1 influence both chloroplast number and leaf starch in proportion to their transcript level. GNC and CGA1 were found to modify the expression of chloroplast localized GLUTAMATE SYNTHASE (GLU1/Fd-GOGAT), which is the primary factor controlling nitrogen assimilation in green tissue. Altering GNC and CGA1 expression was also found to modulate the expression of important chlorophyll biosynthesis genes (GUN4, HEMA1, PORB, and PORC). As previously demonstrated, the CGA1 transgenic plants demonstrated significantly altered timing to a number of developmental events including germination, leaf production, flowering time and senescence. In contrast, the GNC transgenic lines we analyzed maintain relatively normal growth phenotypes outside of differences in chloroplast development. Despite some evidence for partial divergence, results indicate that regulation of both GNC and CGA1 by light, nitrogen, cytokinin, and GA acts to modulate nitrogen assimilation, chloroplast development and starch production. Understanding the mechanisms controlling these processes is important for agricultural biotechnology.
authors.affiliation: Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada.
authors.forename: Darryl
authors.initials: D
authors.lastname: Hudson
authors.forename: David
authors.initials: D
authors.lastname: Guevara
authors.forename: Mahmoud W
authors.initials: MW
authors.lastname: Yaish
authors.forename: Carol
authors.initials: C
authors.lastname: Hannam
authors.forename: Nykoll
authors.initials: N
authors.lastname: Long
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Clarke
authors.forename: Yong-Mei
authors.initials: YM
authors.lastname: Bi
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Rothstein
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002734:Chlorophyll / Q000096:biosynthesis*; D002736:Chloroplasts / Q000378:metabolism; D047369:Chromatin Immunoprecipitation; D003583:Cytokinins / Q000494:pharmacology; D050980:GATA Transcription Factors / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D005875:Gibberellins / Q000494:pharmacology; D009584:Nitrogen / Q000378:metabolism; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D018749:RNA, Plant / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D013213:Starch / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D003583:Cytokinins; D050980:GATA Transcription Factors; D005875:Gibberellins; D012333:RNA, Messenger; D018749:RNA, Plant; D002734:Chlorophyll; D013213:Starch; D000594:Amino Acid Oxidoreductases; C042233:glutamate synthase (ferredoxin); D009584:Nitrogen
references.citation: BMC Genomics. 2010 Mar 22;11:190
references.pmid: 20307264
references.citation: Amino Acids. 2010 Mar;38(3):943-50
references.pmid: 19468822
references.citation: Ann Bot. 2007 Apr;99(4):565-79
references.pmid: 17138581
references.citation: Plant Cell. 1993 Aug;5(8):887-96
references.pmid: 8400871
references.citation: Biosci Biotechnol Biochem. 2007 Jun;71(6):1557-60
references.pmid: 17587690
references.citation: Plant Physiol. 2000 Jan;122(1):49-56
references.pmid: 10631248
references.citation: Development. 2007 Jun;134(11):2073-81
references.pmid: 17507408
references.citation: Plant Cell. 2011 Jan;23(1):69-80
references.pmid: 21224426
references.citation: Proc Natl Acad Sci U S A. 2004 Aug 3;101(31):11506-10
references.pmid: 15272076
references.citation: FEMS Microbiol Rev. 2002 Aug;26(3):223-38
references.pmid: 12165425
references.citation: Plant Cell. 2009 Jun;21(6):1769-80
references.pmid: 19567705
references.citation: Plant Physiol. 2001 Jan;125(1):61-4
references.pmid: 11154297
references.citation: Genes Dev. 1997 Dec 1;11(23):3194-205
references.pmid: 9389651
references.citation: Plant Cell. 2006 Jan;18(1):40-54
references.pmid: 16361392
references.citation: Plant Mol Biol. 2004 Sep;56(1):1-14
references.pmid: 15604725
references.citation: Plant Physiol. 2007 Feb;143(2):941-58
references.pmid: 17208962
references.citation: Curr Opin Microbiol. 2000 Apr;3(2):126-31
references.pmid: 10745000
references.citation: Plant Physiol. 2001 Apr;125(4):1554-7
references.pmid: 11299336
references.citation: Curr Biol. 2002 Apr 30;12(9):757-61
references.pmid: 12007421
references.citation: Curr Opin Plant Biol. 2009 Oct;12(5):574-9
references.pmid: 19709921
references.citation: Science. 2000 Dec 15;290(5499):2110-3
references.pmid: 11118138
references.citation: Plant Mol Biol. 2010 Mar;72(4-5):445-57
references.pmid: 20012672
references.citation: Nature. 2002 Apr 18;416(6882):701-2
references.pmid: 11961544
references.citation: Mol Plant. 2009 Nov;2(6):1198-210
references.pmid: 19995725
references.citation: Plant J. 1998 Dec;16(6):735-43
references.pmid: 10069079
references.citation: Plant Physiol. 2004 Sep;136(1):2483-99
references.pmid: 15375205
references.citation: Genes Dev. 2010 Sep 15;24(18):2093-104
references.pmid: 20844019
references.citation: Proc Natl Acad Sci U S A. 2008 Jul 8;105(27):9433-8
references.pmid: 18591656
references.citation: Plant Physiol. 1985 Feb;77(2):483-5
references.pmid: 16664080
references.citation: Sci STKE. 2007 Oct 09;2007(407):cm5
references.pmid: 17925576
references.citation: Plant Cell. 1997 Jan;9(1):5-19
references.pmid: 9014361
references.citation: J Plant Physiol. 2009 Nov 1;166(16):1775-85
references.pmid: 19540618
references.citation: J Exp Bot. 2002 Apr;53(370):971-7
references.pmid: 11912239
references.citation: Nature. 2008 Jan 24;451(7177):475-9
references.pmid: 18216856
references.citation: Plant Mol Biol. 1997 Jun;34(3):465-76
references.pmid: 9225857
references.citation: Plant J. 2005 Nov;44(4):680-92
references.pmid: 16262716
references.citation: Plant Cell Physiol. 2005 Feb;46(2):339-55
references.pmid: 15695462
references.citation: J Plant Physiol. 2009 Dec 15;166(18):2071-6
references.pmid: 19540016
references.citation: Tree Physiol. 2003 Jun;23(8):553-9
references.pmid: 12730047
references.citation: Trends Plant Sci. 2008 Feb;13(2):85-92
references.pmid: 18262459
references.citation: J Biol Chem. 2010 Jun 4;285(23):17880-95
references.pmid: 20378536
references.citation: Plant Cell. 2007 Sep;19(9):2695-9
references.pmid: 17873097
references.citation: Plant Physiol. 2008 Jun;147(2):707-18
references.pmid: 18417639
references.citation: Proc Natl Acad Sci U S A. 2011 May 31;108(22):9292-7
references.pmid: 21576475
references.citation: Mol Plant. 2010 Nov;3(6):973-96
references.pmid: 20926550
references.citation: BMC Syst Biol. 2009 Sep 03;3:85
references.pmid: 19728870
references.citation: FEBS J. 2009 Aug;276(15):4061-76
references.pmid: 19555410
references.citation: Plant Physiol. 2009 Jan;149(1):7-13
references.pmid: 19126690
references.citation: Plant Physiol. 2007 Jul;144(3):1240-6
references.pmid: 17616507
references.citation: Plant Cell. 2009 Nov;21(11):3535-53
references.pmid: 19920208
references.citation: Plant Mol Biol. 2007 Aug;64(6):733-42
references.pmid: 17571216
references.citation: Plant Cell. 2005 Oct;17(10):2782-90
references.pmid: 16126834
references.citation: J Biol Chem. 2009 Sep 11;284(37):24783-96
references.pmid: 19605356
references.citation: Proc Natl Acad Sci U S A. 2008 Mar 25;105(12):4939-44
references.pmid: 18344319
references.citation: Proc Natl Acad Sci U S A. 2010 Jun 22;107(25):11626-31
references.pmid: 20534526
references.citation: Nature. 2007 Jul 19;448(7151):358-61
references.pmid: 17589502
references.citation: Int J Dev Biol. 2005;49(5-6):557-77
references.pmid: 16096965
references.citation: Trends Plant Sci. 2011 Jan;16(1):19-28
references.pmid: 20833098
references.citation: Trends Plant Sci. 1999 Jul;4(7):250
references.pmid: 10407437
references.citation: Plant Mol Biol. 2007 Dec;65(6):775-97
references.pmid: 17885809
references.citation: Curr Opin Plant Biol. 2003 Feb;6(1):13-9
references.pmid: 12495746
references.citation: Plant Cell. 2006 Oct;18(10):2517-30
references.pmid: 16998069
references.citation: Nature. 1999 Jul 15;400(6741):256-61
references.pmid: 10421366
references.citation: Proc Natl Acad Sci U S A. 2009 May 5;106(18):7660-5
references.pmid: 19380720
references.citation: J Exp Bot. 2007;58(9):2369-87
references.pmid: 17556767
references.citation: Plant Cell. 2007 Apr;19(4):1192-208
references.pmid: 17449805
references.citation: PLoS One. 2007 Aug 08;2(8):e718
references.pmid: 17684564
references.citation: Curr Opin Plant Biol. 2010 Oct;13(5):533-9
references.pmid: 20851038
references.citation: Science. 2005 Jul 29;309(5735):741-5
references.pmid: 15976269
references.citation: J Exp Bot. 2008;59(11):2933-44
references.pmid: 18552353
references.citation: Plant Cell. 2008 Sep;20(9):2460-70
references.pmid: 18812496
references.citation: Plant Cell. 2009 Feb;21(2):403-19
references.pmid: 19244139
references.citation: Plant Cell Physiol. 2007 Jul;48(7):971-83
references.pmid: 17519251
references.citation: Planta. 2005 Nov;222(4):667-77
references.pmid: 16034598
references.citation: Proc Natl Acad Sci U S A. 2009 May 5;106(18):7654-9
references.pmid: 19380736
references.citation: Plant Physiol. 2004 Apr;134(4):1718-32
references.pmid: 15084732
references.citation: Plant Physiol. 1998 Nov;118(3):773-81
references.pmid: 9808721
references.citation: Plant Cell. 2011 May;23(5):1849-60
references.pmid: 21571951
references.citation: Trends Plant Sci. 2006 Sep;11(9):440-8
references.pmid: 16899391
references.citation: Plant J. 2005 Jul;43(1):153-63
references.pmid: 15960624
references.citation: Plant Cell Physiol. 2001 Jan;42(1):85-93
references.pmid: 11158447
references.citation: Plant Mol Biol. 2009 Mar;69(4):419-27
references.pmid: 18855103
references.citation: Plant Cell. 2006 Apr;18(4):792-803
references.pmid: 16595397
references.citation: Plant J. 2005 Oct;44(2):314-33
references.pmid: 16212609
references.citation: Science. 2004 Sep 24;305(5692):1937-41
references.pmid: 15448264
references.citation: Curr Opin Plant Biol. 2001 Jun;4(3):247-53
references.pmid: 11312136
references.citation: Biochemistry. 2005 May 31;44(21):7603-12
references.pmid: 15909975
references.citation: Plant J. 2006 Apr;46(2):336-48
references.pmid: 16623895
references.citation: Plant Biotechnol J. 2011 Sep;9(7):747-58
references.pmid: 21284800
references.citation: Plant Cell. 1998 May;10(5):741-52
references.pmid: 9596633
references.citation: Science. 2003 Apr 11;300(5617):332-6
references.pmid: 12690200
references.citation: Proc Natl Acad Sci U S A. 2004 Jun 8;101(23):8821-6
references.pmid: 15166290
references.citation: Plant Signal Behav. 2010 Feb;5(2):164-7
references.pmid: 20023413
references.citation: PLoS One. 2011;6(5):e19894
references.pmid: 21625438
references.citation: Proc Natl Acad Sci U S A. 2004 Nov 16;101(46):16091-8
references.pmid: 15505214
references.citation: Plant Cell Physiol. 2005 Aug;46(8):1317-25
references.pmid: 15927942
references.citation: Annu Rev Plant Physiol Plant Mol Biol. 1996 Jun;47:569-593
references.pmid: 15012301
references.citation: Biochem Soc Trans. 2005 Feb;33(Pt 1):269-71
references.pmid: 15667323
references.citation: Genes Cells. 2006 Dec;11(12):1381-92
references.pmid: 17121545
references.citation: Plant Cell. 2005 Jan;17(1):92-102
references.pmid: 15608330
references.citation: Curr Opin Plant Biol. 2002 Feb;5(1):33-6
references.pmid: 11788305
references.citation: Annu Rev Plant Biol. 2002;53:203-24
references.pmid: 12221973
references.citation: J Integr Plant Biol. 2010 Aug;52(8):750-61
references.pmid: 20666930