Pubblicazioni

The effect of zeaxanthin as the only xanthophyll on the structure and function of the photosynthetic apparatus in Arabidopsis thaliana.  (2004)

Autori:
HAVAUX M; DALL'OSTO L; CUINE S; GIULIANO G; R. BASSI
Titolo:
The effect of zeaxanthin as the only xanthophyll on the structure and function of the photosynthetic apparatus in Arabidopsis thaliana.
Anno:
2004
Tipologia prodotto:
Articolo in Rivista
Tipologia ANVUR:
Articolo su rivista
Lingua:
Inglese
Referee:
Nome rivista:
JBC
ISSN Rivista:
0021-9258
N° Volume:
279
Intervallo pagine:
13878-13888
Parole chiave:
zeaxanthin; xanthophylls; photoprotection; non-photochemical quenching; chloroplast
Breve descrizione dei contenuti:
In green plants, the xanthophyll carotenoid zeaxanthin is synthesized transiently under conditions of excess light energy and participates in photoprotection. In the Arabidopsis lut2 npq2 double mutant, all xanthophylls were replaced constitutively by zeaxanthin, the only xanthophyll whose synthesis was not impaired. The relative proportions of the different chlorophyll antenna proteins were strongly affected with respect to the wild-type strain. The major antenna, LHCII, did not form trimers, and its abundance was strongly reduced as was CP26, albeit to a lesser extent. In contrast, CP29, CP24, LHCI proteins, and the PSI and PSII core complexes did not undergo major changes. PSII-LHCII supercomplexes were not detectable while the PSI-LHCI supercomplex remained unaffected. The effect of zeaxanthin accumulation on the stability of the different Lhc proteins was uneven: the LHCII proteins from lut2 npq2 had a lower melting temperature as compared with the wild-type complex while LHCI showed increased resistance to heat denaturation. Consistent with the loss of LHCII, light-state 1 to state 2 transitions were suppressed, the photochemical efficiency in limiting light was reduced and photosynthesis was saturated at higher light intensities in lut2 npq2 leaves, resulting in a photosynthetic phenotype resembling that of high light-acclimated leaves. Zeaxanthin functioned in vivo as a light-harvesting accessory pigment in lut2 npq2 chlorophyll antennae. As a whole, the in vivo data are consistent with the results obtained by using recombinant Lhc proteins reconstituted in vitro with purified zeaxanthin. While PSII photoinhibition was similar in wild type and lut2 npq2 exposed to high light at low temperature, the double mutant was much more resistant to photooxidative stress and lipid peroxidation than the wild type. The latter observation is consistent with an antioxidant and lipid protective role of zeaxanthin in vivo
Id prodotto:
24432
Handle IRIS:
11562/304931
depositato il:
27 luglio 2007
ultima modifica:
20 marzo 2018
Citazione bibliografica:
HAVAUX M; DALL'OSTO L; CUINE S; GIULIANO G; R. BASSI, The effect of zeaxanthin as the only xanthophyll on the structure and function of the photosynthetic apparatus in Arabidopsis thaliana. «JBC» , vol. 2792004pp. 13878-13888

Consulta la scheda completa presente nel repository istituzionale della Ricerca di Ateneo IRIS

Progetti Collegati
Titolo Dipartimento Responsabili
La risposta allo stress ossidativo in Arabidopsis mutata nella via di biosintesi dei carotenoidi Dipartimento Biotecnologie Roberto Bassi
<<indietro

Attività

Strutture