First published online March 9, 2007; 10.1105/tpc.106.049114
The Plant Cell 19:1048-1064 (2007)
© 2007 American Society of Plant Biologists
The Arabidopsis aba4-1 Mutant Reveals a Specific Function for Neoxanthin in Protection against Photooxidative Stress[W]
Luca Dall'Ostoa,
Stefano Cazzanigaa,
Helen Northb,
Annie Marion-Pollb and
Roberto Bassia,c,1
a Dipartimento Scientifico e Tecnologico, Università di Verona, I-37134 Verona, Italy
b Laboratoire de Biologie des Sémences, Unité Mixte de Recherche 204, Institut National de la Recherche Agronomique–Institut National Agronomique Paris-Grignon, Institut Jean-Pierre Bourgin, 78026 Versailles Cedex, France
c Laboratoire de Génétique et Biophysique des Plantes, Département d'Ecophysiologie Végétale et Microbiologie, Unité Mixte de Recherche 163, Commissariat à l'Energie Atomique–Centre National de la Recherche Scientifique, Université de la Méditerranée, 13288 Marseille, France
1 To whom correspondence should be addressed. E-mail bassi{at}sci.univr.it; fax 39-045-802-7929.
The aba4-1 mutant completely lacks neoxanthin but retains all other xanthophyll species. The missing neoxanthin in light-harvesting complex (Lhc) proteins is compensated for by higher levels of violaxanthin, albeit with lower capacity for photoprotection compared with proteins with wild-type levels of neoxanthin. Detached leaves of aba4-1 were more sensitive to oxidative stress than the wild type when exposed to high light and incubated in a solution of photosensitizer agents. Both treatments caused more rapid pigment bleaching and lipid oxidation in aba4-1 than wild-type plants, suggesting that neoxanthin acts as an antioxidant within the photosystem II (PSII) supercomplex in thylakoids. While neoxanthin-depleted Lhc proteins and leaves had similar sensitivity as the wild type to hydrogen peroxide and singlet oxygen, they were more sensitive to superoxide anions. aba4-1 intact plants were not more sensitive than the wild type to high-light stress, indicating the existence of compensatory mechanisms of photoprotection involving the accumulation of zeaxanthin. However, the aba4-1 npq1 double mutant, lacking zeaxanthin and neoxanthin, underwent stronger PSII photoinhibition and more extensive oxidation of pigments than the npq1 mutant, which still contains neoxanthin. We conclude that neoxanthin preserves PSII from photoinactivation and protects membrane lipids from photooxidation by reactive oxygen species. Neoxanthin appears particularly active against superoxide anions produced by the Mehler's reaction, whose rate is known to be enhanced in abiotic stress conditions.
This article has been cited by other articles:
|
|
|
|
 
Z. Chen and D. R. Gallie
Dehydroascorbate Reductase Affects Non-photochemical Quenching and Photosynthetic Performance
J. Biol. Chem.,
August 1, 2008;
283(31):
21347 - 21361.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
G. Bonente, B. D. Howes, S. Caffarri, G. Smulevich, and R. Bassi
Interactions between the Photosystem II Subunit PsbS and Xanthophylls Studied in Vivo and in Vitro
J. Biol. Chem.,
March 28, 2008;
283(13):
8434 - 8445.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Mozzo, L. Dall'Osto, R. Hienerwadel, R. Bassi, and R. Croce
Photoprotection in the Antenna Complexes of Photosystem II: ROLE OF INDIVIDUAL XANTHOPHYLLS IN CHLOROPHYLL TRIPLET QUENCHING
J. Biol. Chem.,
March 7, 2008;
283(10):
6184 - 6192.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Havaux, L. Dall'Osto, and R. Bassi
Zeaxanthin Has Enhanced Antioxidant Capacity with Respect to All Other Xanthophylls in Arabidopsis Leaves and Functions Independent of Binding to PSII Antennae
Plant Physiology,
December 1, 2007;
145(4):
1506 - 1520.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
L. Dall'Osto, A. Fiore, S. Cazzaniga, G. Giuliano, and R. Bassi
Different Roles of {alpha}- and -Branch Xanthophylls in Photosystem Assembly and Photoprotection
J. Biol. Chem.,
November 30, 2007;
282(48):
35056 - 35068.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
