title: The significance of cysteine synthesis for acclimation to high light conditions.
abstract: Situations of excess light intensity are known to result in the emergence of reactive oxygen species that originate from the electron transport chain in chloroplasts. The redox state of glutathione and its biosynthesis contribute importantly to the plant's response to this stress. In this study we analyzed the significance of cysteine synthesis for long-term acclimation to high light conditions in Arabidopsis thaliana. Emphasis was put on the rate-limiting step of cysteine synthesis, the formation of the precursor O-acetylserine (OAS) that is catalyzed by serine acetyltransferase (SERAT). Wild type Arabidopsis plants responded to the high light condition (800 μmol m(-2) s(-1) for 10 days) with synthesis of photo-protective anthocyanins, induction of total SERAT activity and elevated glutathione levels when compared to the control condition (100 μmol m(-2) s(-1)). The role of cysteine synthesis in chloroplasts was probed in mutant plants lacking the chloroplast isoform SERAT2;1 (serat2;1) and two knock-out alleles of CYP20-3, a positive interactor of SERAT in the chloroplast. Acclimation to high light resulted in a smaller growth enhancement than wild type in the serat2;1 and cyp20-3 mutants, less induction of total SERAT activity and OAS levels but similar cysteine and glutathione concentrations. Expression analysis revealed no increase in mRNA of the chloroplast SERAT2;1 encoding SERAT2;1 gene but up to 4.4-fold elevated SERAT2;2 mRNA levels for the mitochondrial SERAT isoform. Thus, lack of chloroplast SERAT2;1 activity or its activation by CYP20-3 prevents the full growth response to high light conditions, but the enhanced demand for glutathione is likely mediated by synthesis of OAS in the mitochondria. In conclusion, cysteine synthesis in the chloroplast is important for performance but is dispensable for survival under long-term exposure to high light and can be partially complemented by cysteine synthesis in mitochondria.
authors: Plant Molecular Biology, Centre for Organismal Studies, University of Heidelberg Heidelberg, Germany.
authors: Anna
authors: A
authors: Speiser
authors: Plant Molecular Biology, Centre for Organismal Studies, University of Heidelberg Heidelberg, Germany.
authors: Stefan
authors: S
authors: Haberland
authors: Molecular Plant Physiology, Max Planck Institute of Molecular Plant Physiology Potsdam, Germany.
authors: Mutsumi
authors: M
authors: Watanabe
authors: Plant Molecular Biology, Centre for Organismal Studies, University of Heidelberg Heidelberg, Germany.
authors: Markus
authors: M
authors: Wirtz
authors: Plant Biochemistry and Physiology, University of Bielefeld Bielefeld, Germany.
authors: Karl-Josef
authors: KJ
authors: Dietz
authors: RIKEN Center for Sustainable Resource Science Yokohama, Japan ; Graduate School of Pharmaceutical Sciences, Chiba University Chiba, Japan.
authors: Kazuki
authors: K
authors: Saito
authors: Plant Molecular Biology, Centre for Organismal Studies, University of Heidelberg Heidelberg, Germany.
authors: Rüdiger
authors: R
authors: Hell
keywords: CYP20-3; SERAT; chloroplasts; glutathione; high light stress; mitochondria
references: Plant Physiol. 2013 Oct;163(2):959-72
references: 24001608
references: Trends Plant Sci. 2000 May;5(5):193-8
references: 10785664
references: Plant Cell. 2010 Apr;22(4):1216-31
references: 20424176
references: Plant Physiol. 2008 Oct;148(2):1055-67
references: 18753283
references: J Exp Bot. 2002 May;53(372):1249-54
references: 11997373
references: Plant Cell Environ. 2006 Feb;29(2):269-81
references: 17080642
references: FEBS Lett. 2007 Jul 10;581(17):3131-8
references: 17561001
references: Trends Biochem Sci. 1992 Feb;17(2):61-6
references: 1566330
references: Mol Plant. 2009 Mar;2(2):344-56
references: 19825619
references: Biochem J. 1967 Aug;104(2):627-33
references: 6048802
references: Annu Rev Plant Biol. 2008;59:143-66
references: 18444899
references: Biochem J. 2007 Jan 1;401(1):287-97
references: 16928193
references: Plant Cell. 1998 Jul;10(7):1135-49
references: 9668133
references: Plant Physiol. 2012 Sep;160(1):274-88
references: 22829322
references: Plant Physiol. 1997 Feb;113(2):575-86
references: 9046598
references: Plant Physiol. 2001 Jun;126(2):564-74
references: 11402187
references: Photochem Photobiol. 2008 Nov-Dec;84(6):1343-8
references: 19067955
references: Plant Cell Environ. 2012 Feb;35(2):454-84
references: 21777251
references: Eur J Biochem. 1995 Jan 15;227(1-2):500-9
references: 7851429
references: Plant Cell Physiol. 2014 Jan;55(1):64-73
references: 24192298
references: Plant Cell. 2008 Jan;20(1):168-85
references: 18223034
references: Arabidopsis Book. 2011;9:e0142
references: 22303267
references: Proc Natl Acad Sci U S A. 2009 Jun 2;106(22):9109-14
references: 19451637
references: Proc Natl Acad Sci U S A. 1998 Sep 29;95(20):12049-54
references: 9751788
references: Adv Bioinformatics. 2008;2008:420747
references: 19956698
references: Plant Physiol. 2004 Apr;134(4):1268-82
references: 15051864
references: J Biol Chem. 2010 Oct 22;285(43):32810-7
references: 20720017
references: Physiol Plant. 2010 Feb;138(2):215-25
references: 19947975
references: Plant Physiol. 2004 Apr;134(4):1248-67
references: 15047905
references: Trends Plant Sci. 2013 Jan;18(1):18-29
references: 23040678
references: Plant Physiol. 2008 Jan;146(1):310-20
references: 18024555
references: Annu Rev Plant Biol. 2009;60:455-84
references: 19575589
references: Plant Physiol. 2011 Jan;155(1):2-18
references: 21205630
references: Plant Cell Physiol. 2004 Jan;45(1):1-8
references: 14749480
references: Genome Biol. 2005;6(7):226
references: 15998457
references: J Biol Chem. 2012 Aug 10;287(33):27941-7
references: 22730323
references: J Biol Chem. 2003 Aug 22;278(34):31848-52
references: 12923164
references: Photosynth Res. 2005 Dec;86(3):435-57
references: 16315075
references: Annu Rev Plant Physiol Plant Mol Biol. 1998 Jun;49:249-279
references: 15012235
references: Plant Mol Biol. 1997 Dec;35(6):873-92
references: 9426607
references: Proc Natl Acad Sci U S A. 2013 Jun 4;110(23):9559-64
references: 23671085
references: Plant Cell. 2008 Sep;20(9):2484-96
references: 18776059
references: Plant Cell. 2010 Feb;22(2):403-16
references: 20179139
references: Proc Natl Acad Sci U S A. 2008 Oct 21;105(42):16386-91
references: 18845687
references: Amino Acids. 2003;24(1-2):195-203
references: 12624753
references: J Biol Chem. 1994 Mar 18;269(11):7863-8
references: 8132503
references: Arabidopsis Book. 2011;9:e0154
references: 22303278
references: Mol Cell Proteomics. 2006 Jan;5(1):114-33
references: 16207701
references: Plant Physiol. 2005 Oct;139(2):806-21
references: 16183842
references: Philos Trans R Soc Lond B Biol Sci. 2014 Mar 03;369(1640):20130424
references: 24591725
references: Mol Plant. 2009 May;2(3):390-406
references: 19825624
references: Plant Cell. 2011 Apr;23(4):1512-22
references: 21487097
references: J Biol Chem. 2002 Aug 23;277(34):30629-34
references: 12063244
references: Plant Cell Environ. 2012 Feb;35(2):259-70
references: 21486305
references: J Plant Physiol. 2013 Nov 15;170(17):1501-16
references: 23850030
references: Nucleic Acids Res. 1991 Mar 25;19(6):1349
references: 2030957
references: Plant Mol Biol. 2003 Mar;51(4):589-98
references: 12650624