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| Hauptseite > Publikationsdatenbank > Slowly reversible de-epoxidation of lutein-epoxide in deep shade leaves of a tropical tree legume may 'lock-in' lutein-based photoprotection during acclimation to strong light |
| Hauptseite > Publikationsdatenbank > Slowly reversible de-epoxidation of lutein-epoxide in deep shade leaves of a tropical tree legume may 'lock-in' lutein-based photoprotection during acclimation to strong light |
| Journal Article | PreJuSER-40448 |
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2005
Univ. Press
Oxford
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Please use a persistent id in citations: doi:10.1093/jxb/eri012
Abstract: The kinetics of response to strong light have been examined in deeply shaded leaves of the tropical tree legume (Inga sp.) which have extraordinarily high levels of the alpha-xanthophyll lutein-epoxide that are co-located in pigment-protein complexes of the photosynthetic apparatus with the beta-xanthophyll violaxanthin. As in other species, rapidly reversible photoprotection (measured as non-photochemical chlorophyll fluorescence quenching) is initiated within the time frame of sun-flecks (minutes), before detectable conversion of violaxanthin to antheraxanthin or zeaxanthin. Photoprotection is stabilized within hours of exposure to strong light by simultaneously engaging the reversible violaxanthin cycle and a slowly reversible conversion of lutein-epoxide to lutein. It is proposed that this lutein 'locks in' a primary mechanism of photoprotection during photoacclimation in this species, converting efficient light-harvesting antennae of the shade plant into potential excitation dissipating centres. It is hypothesized that lutein occupies sites L2 and V1 in light-harvesting chlorophyll protein complexes of photosystem II, facilitating enhanced photoprotection through the superior singlet and/or triplet chlorophyll quenching capacity of lutein.
Keyword(s): Acclimatization: physiology (MeSH) ; Circadian Rhythm (MeSH) ; Electron Transport (MeSH) ; Fabaceae: metabolism (MeSH) ; Fabaceae: physiology (MeSH) ; Fabaceae: radiation effects (MeSH) ; Light (MeSH) ; Lutein: analogs & derivatives (MeSH) ; Lutein: metabolism (MeSH) ; Photosynthetic Reaction Center Complex Proteins: physiology (MeSH) ; Pigments, Biological: metabolism (MeSH) ; Plant Leaves: physiology (MeSH) ; Trees: physiology (MeSH) ; Tropical Climate (MeSH) ; Photosynthetic Reaction Center Complex Proteins ; Pigments, Biological ; Lutein ; J ; Inga sp. (auto) ; lutein-epoxide (auto) ; photoacclimation (auto) ; photoprotection (auto) ; photosynthesis (auto) ; xanthophyll cycles (auto)
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