%0 Journal Article %A Matsubara, S. %A Naumann, M. %A Martin, J. M. %A Nichol, C. %A Rascher, U. %A Morosinotto, T. %A Bassi, R. %A Osmond, B. %T 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 %J The journal of experimental botany %V 56 %@ 0022-0957 %C Oxford %I Univ. Press %M PreJuSER-40448 %P 461 - 468 %D 2005 %Z Record converted from VDB: 12.11.2012 %X 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. %K Acclimatization: physiology %K Circadian Rhythm %K Electron Transport %K Fabaceae: metabolism %K Fabaceae: physiology %K Fabaceae: radiation effects %K Light %K Lutein: analogs & derivatives %K Lutein: metabolism %K Photosynthetic Reaction Center Complex Proteins: physiology %K Pigments, Biological: metabolism %K Plant Leaves: physiology %K Trees: physiology %K Tropical Climate %K Photosynthetic Reaction Center Complex Proteins (NLM Chemicals) %K Pigments, Biological (NLM Chemicals) %K Lutein (NLM Chemicals) %K J (WoSType) %F PUB:(DE-HGF)16 %9 Journal Article %$ pmid:15501906 %U <Go to ISI:>//WOS:000226610500015 %R 10.1093/jxb/eri012 %U https://juser.fz-juelich.de/record/40448