title: The solar action spectrum of photosystem II damage.
abstract: The production of oxygen and the supply of energy for life on earth rely on the process of photosynthesis using sunlight. Paradoxically, sunlight damages the photosynthetic machinery, primarily photosystem II (PSII), leading to photoinhibition and loss of plant performance. However, there is uncertainty about which wavelengths are most damaging to PSII under sunlight. In this work we examined this in a simple experiment where Arabidopsis (Arabidopsis thaliana) leaves were exposed to different wavelengths of sunlight by dispersing the solar radiation across the surface of the leaf via a prism. To isolate only the process of photodamage, the repair of photodamaged PSII was inhibited by infiltration of chloramphenicol into the exposed leaves. The extent of photodamage was then measured as the decrease in the maximum quantum yield of PSII using an imaging pulse amplitude modulation fluorometer. Under the experimental light conditions, photodamage to PSII occurred most strongly in regions exposed to ultraviolet (UV) or yellow light. The extent of UV photodamage under incident sunlight would be greater than we observed when one corrects for the optical efficiency of our system. Our results suggest that photodamage to PSII under sunlight is primarily associated with UV rather than photosynthetically active light wavelengths.
authors.affiliation: Australian Research Council Centre of Excellence in Plant Energy Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia. shunichi.takahashi@anu.edu.au
authors.forename: Shunichi
authors.initials: S
authors.lastname: Takahashi
authors.forename: Sara E
authors.initials: SE
authors.lastname: Milward
authors.forename: Wataru
authors.initials: W
authors.lastname: Yamori
authors.forename: John R
authors.initials: JR
authors.lastname: Evans
authors.forename: Warwick
authors.initials: W
authors.lastname: Hillier
authors.forename: Murray R
authors.initials: MR
authors.lastname: Badger
mesh_terms: D017360:Arabidopsis / Q000528:radiation effects*; D045332:Photosystem II Protein Complex / Q000378:metabolism* / Q000528:radiation effects*; D018515:Plant Leaves / Q000528:radiation effects; D013472:Sunlight
chemical_list: D045332:Photosystem II Protein Complex
references.citation: Biochim Biophys Acta. 1993 Jul 5;1143(2):113-34
references.pmid: 8318516
references.citation: Plant Cell. 1993 Feb;5(2):171-179
references.pmid: 12271060
references.citation: Biochim Biophys Acta. 2006 Jul;1757(7):742-9
references.pmid: 16784721
references.citation: Trends Plant Sci. 2009 Apr;14(4):200-5
references.pmid: 19303349
references.citation: Plant Physiol. 1966 Jun;41(6):1037-43
references.pmid: 16656345
references.citation: Biochemistry. 2004 Sep 7;43(35):11321-30
references.pmid: 15366942
references.citation: Proc Natl Acad Sci U S A. 1996 Mar 5;93(5):2213-8
references.pmid: 11607639
references.citation: Biochim Biophys Acta. 2006 Mar;1757(3):198-205
references.pmid: 16551463
references.citation: Biochemistry. 2005 Jun 14;44(23):8494-9
references.pmid: 15938639
references.citation: Biochim Biophys Acta. 2004 Jun 28;1657(1):23-32
references.pmid: 15238209
references.citation: Biochim Biophys Acta. 2007 Jun;1767(6):414-21
references.pmid: 17207454
references.citation: Plant Physiol. 2009 Mar;149(3):1568-78
references.pmid: 19144767
references.citation: Plant Physiol. 2002 Jul;129(3):1359-67
references.pmid: 12114589
references.citation: Nature. 2002 Dec 19-26;420(6917):829-32
references.pmid: 12490952
references.citation: Plant Physiol. 2005 Jan;137(1):263-73
references.pmid: 15618415
references.citation: Plant Physiol. 1995 Dec;109(4):1159-66
references.pmid: 8539286
references.citation: Trends Plant Sci. 2008 Apr;13(4):178-82
references.pmid: 18328775
references.citation: Plant Physiol. 2000 Nov;124(3):1275-84
references.pmid: 11080303
references.citation: Arch Biochem Biophys. 2004 Sep 1;429(1):71-80
references.pmid: 15288811
references.citation: Curr Opin Plant Biol. 2002 Jun;5(3):218-23
references.pmid: 11960739
references.citation: Biochim Biophys Acta. 2006 Feb;1757(2):123-9
references.pmid: 16500615
references.citation: Photosynth Res. 2005 Jun;84(1-3):35-41
references.pmid: 16049752
references.citation: Biochim Biophys Acta. 2005 Jul 15;1708(3):352-61
references.pmid: 15955527
references.citation: Plant Physiol. 2009 Mar;149(3):1560-7
references.pmid: 19118124
references.citation: Biochim Biophys Acta. 2005 Jan 7;1706(1-2):68-80
references.pmid: 15620366
references.citation: Plant Physiol. 2007 May;144(1):487-94
references.pmid: 17400706
references.citation: EMBO J. 2001 Oct 15;20(20):5587-94
references.pmid: 11598002
references.citation: Trends Plant Sci. 1999 Apr;4(4):130-135
references.pmid: 10322546
references.citation: Biochemistry. 1994 Mar 15;33(10):3087-95
references.pmid: 8130223
references.citation: Plant Physiol. 2001 Jun;126(2):485-93
references.pmid: 11402179
references.citation: Biochemistry. 1990 Jul 3;29(26):6179-86
references.pmid: 2207066
references.citation: Plant Cell Physiol. 2006 Mar;47(3):391-400
references.pmid: 16415063
references.citation: Proc Natl Acad Sci U S A. 1984 Mar;81(5):1380-4
references.pmid: 16593427
references.citation: Annu Rev Plant Physiol Plant Mol Biol. 1999 Jun;50:333-359
references.pmid: 15012213