title: The role of autophagy in chloroplast degradation and chlorophagy in immune defenses during Pst DC3000 (AvrRps4) infection.
abstract: BACKGROUND
  Chlorosis of leaf tissue normally observed during pathogen infection may result from the degradation of chloroplasts. There is a growing evidence to suggest that the chloroplast plays a significant role during pathogen infection. Although most degradation of the organelles and cellular structures in plants is mediated by autophagy, its role in chloroplast catabolism during pathogen infection is largely unknown.
  
  
  RESULTS
  In this study, we investigated the function of autophagy in chloroplast degradation during avirulent Pst DC3000 (AvrRps4) infection. We examined the expression of defensive marker genes and suppression of bacterial growth using the electrolyte leakage assay in normal light (N) and low light (L) growing environments of wild-type and atg5-1 plants during pathogen treatment. Stroma-targeted GFP proteins (CT-GFP) were observed with LysoTracker Red (LTR) staining of autophagosome-like structures in the vacuole. The results showed that Arabidopsis expressed a significant number of small GFP-labeled bodies when infected with avirulent Pst DC3000 (AvrRps4). While barely detectable, there were small GFP-labeled bodies in plants with the CT-GFP expressing atg5-1 mutation. The results showed that chloroplast degradation depends on autophagy and this may play an important role in inhibiting pathogen growth.
  
  
  CONCLUSIONS
  Autophagy plays a role in chloroplast degradation in Arabidopsis during avirulent Pst DC3000 (AvrRps4) infection. Autophagy dependent chloroplast degradation may be the primary source of reactive oxygen species (ROS) as well as the pathogen-response signaling molecules that induce the defense response.
authors.affiliation: MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, Guangdong, China ; College of Life Science, Guangdong Key Laboratory of Biotechnology for Plant Development, South China Normal University, Guangzhou, Guangdong, China.
authors.forename: Junjian
authors.initials: J
authors.lastname: Dong
authors.forename: Wenli
authors.initials: W
authors.lastname: Chen
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000276:immunology* / Q000382:microbiology*; D001343:Autophagy / Q000187:drug effects; D002734:Chlorophyll / Q000378:metabolism; D002736:Chloroplasts / Q000187:drug effects / Q000378:metabolism*; D060467:Disease Resistance / Q000187:drug effects / Q000235:genetics; D005453:Fluorescence; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant / Q000235:genetics; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000494:pharmacology; D018942:Macrolides / Q000494:pharmacology; D058503:Mesophyll Cells / Q000187:drug effects / Q000378:metabolism / Q000382:microbiology; D010641:Phenotype; D010935:Plant Diseases / Q000276:immunology / Q000382:microbiology*; D057865:Plant Immunity / Q000187:drug effects / Q000235:genetics; D018515:Plant Leaves / Q000187:drug effects / Q000276:immunology / Q000382:microbiology; D044224:Pseudomonas syringae / Q000472:pathogenicity / Q000502:physiology*; D014617:Vacuoles / Q000187:drug effects / Q000378:metabolism; D014774:Virulence / Q000187:drug effects / Q000235:genetics
chemical_list: D018942:Macrolides; D002734:Chlorophyll; D049452:Green Fluorescent Proteins; C036978:concanamycin A; D006861:Hydrogen Peroxide
references.citation: New Phytol. 2012 Jul;195(1):85-96
references.pmid: 22497243
references.citation: J Exp Bot. 2011 Jan;62(1):331-43
references.pmid: 20937730
references.citation: Plant Cell Physiol. 2004 Mar;45(3):265-74
references.pmid: 15047874
references.citation: J Lab Clin Med. 1954 Aug;44(2):301-7
references.pmid: 13184240
references.citation: Plant Physiol. 2008 Sep;148(1):142-55
references.pmid: 18614709
references.citation: Curr Biol. 2007 Mar 20;17(6):499-508
references.pmid: 17350264
references.citation: Cell Host Microbe. 2012 Mar 15;11(3):253-63
references.pmid: 22423965
references.citation: Plant J. 2010 May;62(3):483-93
references.pmid: 20136727
references.citation: Plant Physiol. 1991 Aug;96(4):1193-5
references.pmid: 16668319
references.citation: PLoS One. 2010 Jul 29;5(7):e11883
references.pmid: 20686696
references.citation: Photochem Photobiol Sci. 2011 Jun;10(6):947-55
references.pmid: 21336371
references.citation: Science. 1997 Jun 27;276(5321):2039-42
references.pmid: 9197266
references.citation: Trends Cell Biol. 2008 Jul;18(7):311-4
references.pmid: 18508269
references.citation: J Biol Chem. 2002 Sep 6;277(36):33105-14
references.pmid: 12070171
references.citation: Plant Physiol. 2006 Jun;141(2):391-6
references.pmid: 16760493
references.citation: Cell Microbiol. 2012 May;14(5):669-81
references.pmid: 22233353
references.citation: Cell. 2003 Feb 7;112(3):379-89
references.pmid: 12581527
references.citation: PLoS Pathog. 2010 Jul 01;6:e1000970
references.pmid: 20617163
references.citation: Plant Cell Physiol. 2006 Dec;47(12):1641-52
references.pmid: 17085765
references.citation: Autophagy. 2009 Jul;5(5):736-7
references.pmid: 19395861
references.citation: Arabidopsis Book. 2002;1:e0039
references.pmid: 22303207
references.citation: Science. 2011 Dec 9;334(6061):1401-4
references.pmid: 22158818
references.citation: Plant Physiol. 1991 Jun;96(2):355-62
references.pmid: 16668193
references.citation: PLoS One. 2012;7(9):e45673
references.pmid: 23029176
references.citation: Curr Top Microbiol Immunol. 2009;335:287-306
references.pmid: 19802571
references.citation: Plant Cell. 2008 Sep;20(9):2339-56
references.pmid: 18790826
references.citation: PLoS Pathog. 2012 Feb;8(2):e1002513
references.pmid: 22346749
references.citation: FEMS Microbiol Rev. 2011 Nov;35(6):1100-25
references.pmid: 21517912
references.citation: Plant J. 2000 Jun;22(6):523-9
references.pmid: 10886772
references.citation: FEBS Lett. 2010 Apr 2;584(7):1350-8
references.pmid: 20079356
references.citation: Autophagy. 2005 Jul;1(2):75-83
references.pmid: 16874024
references.citation: Mol Plant Microbe Interact. 2010 Nov;23(11):1368-80
references.pmid: 20923348
references.citation: Plant Physiol. 2012 Oct;160(2):1081-96
references.pmid: 22926319
references.citation: Plant Cell. 2000 Jun;12(6):917-32
references.pmid: 10852937
references.citation: Traffic. 2005 Jan;6(1):56-65
references.pmid: 15569245
references.citation: Cell Host Microbe. 2008 Mar 13;3(3):126-35
references.pmid: 18329612
references.citation: Arch Biochem Biophys. 2007 Jun 15;462(2):245-53
references.pmid: 17475204
references.citation: J Cell Sci. 2001 Oct;114(Pt 20):3619-29
references.pmid: 11707514
references.citation: Planta. 2012 Jan;235(1):99-110
references.pmid: 21853253
references.citation: Cell. 2006 Feb 24;124(4):803-14
references.pmid: 16497589
references.citation: Proc Natl Acad Sci U S A. 1982 Mar;79(6):1889-92
references.pmid: 6952238
references.citation: New Phytol. 2011 Jul;191(1):107-119
references.pmid: 21434927
references.citation: Plant Physiol. 2009 Feb;149(2):885-93
references.pmid: 19074627
references.citation: Plant Cell. 2009 Sep;21(9):2914-27
references.pmid: 19773385
references.citation: Mol Plant Microbe Interact. 2003 Dec;16(12):1135-44
references.pmid: 14651347
references.citation: Curr Opin Plant Biol. 2005 Aug;8(4):397-403
references.pmid: 15939662
references.citation: Science. 2002 Mar 1;295(5560):1722-6
references.pmid: 11872842
references.citation: Cell. 2009 May 15;137(4):773-83
references.pmid: 19450522
references.citation: Plant Cell Environ. 2010 May;33(5):828-39
references.pmid: 20040062
references.citation: Plant Cell. 2004 Nov;16(11):2967-83
references.pmid: 15494556
references.citation: Plant Physiol. 2011 May;156(1):286-300
references.pmid: 21398259
references.citation: Planta. 2006 Dec;225(1):1-12
references.pmid: 16807755
references.citation: Plant J. 2005 Aug;43(4):506-19
references.pmid: 16098105
references.citation: PLoS Pathog. 2011 Nov;7(11):e1002318
references.pmid: 22072959
references.citation: Plant J. 2003 Aug;35(4):545-55
references.pmid: 12904216
references.citation: Proc Natl Acad Sci U S A. 1992 Sep 1;89(17):8068-72
references.pmid: 1518831
references.citation: Mol Biol Cell. 2003 Jan;14(1):129-41
references.pmid: 12529432
references.citation: Plant Cell Physiol. 2012 Aug;53(8):1355-65
references.pmid: 22764279
references.citation: Genetics. 2008 Mar;178(3):1339-53
references.pmid: 18245858
references.citation: J Exp Bot. 2005 Mar;56(413):787-97
references.pmid: 15699062
references.citation: J Cell Sci. 2000 Nov;113 ( Pt 22):3921-30
references.pmid: 11058079
references.citation: PLoS One. 2012;7(4):e34995
references.pmid: 22514699
references.citation: Plant Physiol. 2010 Nov;154(3):1196-209
references.pmid: 20807997
references.citation: Nat Rev Mol Cell Biol. 2004 Apr;5(4):305-15
references.pmid: 15071555
references.citation: Plant Physiol. 2007 Jan;143(1):291-9
references.pmid: 17098847
references.citation: Cell. 2005 May 20;121(4):567-577
references.pmid: 15907470
references.citation: Autophagy. 2009 Feb;5(2):270-2
references.pmid: 19182523
references.citation: Cell. 2008 Feb 8;132(3):449-62
references.pmid: 18267075
references.citation: Trends Plant Sci. 2012 Sep;17(9):526-37
references.pmid: 22694835
references.citation: PLoS One. 2012;7(3):e33817
references.pmid: 22448275
references.citation: Plant Physiol. 2005 Aug;138(4):2097-110
references.pmid: 16040659