<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Camarero, Jesús Julio</style></author><author><style face="normal" font="default" size="100%">Olano, José Miguel</style></author><author><style face="normal" font="default" size="100%">Arroyo Alfaro, Sandra Jackeline</style></author><author><style face="normal" font="default" size="100%">Fernández-Marín, Beatriz</style></author><author><style face="normal" font="default" size="100%">Becerril, José Maria</style></author><author><style face="normal" font="default" size="100%">García-Plazaola, José Ignacio</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Photoprotection mechanisms in Quercus ilex under contrasting climatic conditions</style></title><secondary-title><style face="normal" font="default" size="100%">Flora - Morphology, Distribution, Functional Ecology of Plants</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">ecotypes</style></keyword><keyword><style  face="normal" font="default" size="100%">Holm oak</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean</style></keyword><keyword><style  face="normal" font="default" size="100%">photoprotection</style></keyword><keyword><style  face="normal" font="default" size="100%">Trichomes</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2012</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2012///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://linkinghub.elsevier.com/retrieve/pii/S0367253012000783</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">207</style></volume><pages><style face="normal" font="default" size="100%">557 - 564</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Acclimation to local conditions may produce adaptive responses in plants subjected to diverse climatic stresses. However, it has not been assessed how local adaptation and phenotypic plasticity contribute to photoprotection mechanisms in response to contrasting climatic conditions in Mediterranean tree species. We analyzed photoprotectionmechanisms inmature trees oftheMediterranean evergreen oak Quercus ilex at three sites with contrasting climatic conditions, i.e. xeric, continental and mesic sites. We studied morphological and physiological parameters indicative of photoprotection in adult trees in the ﬁeld. In order to establish whether these parameters were genetically determined we compared adults with seedlings germinated from acorns of the three sites and grown under common greenhouse conditions. In the ﬁeld we found no signiﬁcant differences in most of the physiological parameters in summer, but in winter the adulttrees fromthe continental site were photoinhibited. In contrast,there were signiﬁcant differences between seedlings in most photoprotective parameters evaluated. Morphological traits such as trichome density and leaf reﬂectance differed between populations, both in ﬁeld-grown trees and in greenhouse-grown seedlings, being higher in all cases in plants from the xeric site than elsewhere. Our ﬁndings suggest the existence of constitutive differences in leaf photoprotection mechanisms among Q. ilex populations. These divergences may represent an inherent source for more stress tolerant ecotypes in the face of changing climatic conditions.</style></abstract><issue><style face="normal" font="default" size="100%">8</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;publisher: Elsevier GmbH.</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Javier Peguero-Pina, Jose</style></author><author><style face="normal" font="default" size="100%">Sancho-Knapik, Domingo</style></author><author><style face="normal" font="default" size="100%">Morales, Fermín</style></author><author><style face="normal" font="default" size="100%">Flexas, Jaume</style></author><author><style face="normal" font="default" size="100%">Gil-Pelegrín, Eustaquio</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Differential photosynthetic performance and photoprotection mechanisms of three Mediterranean evergreen oaks under severe drought stress</style></title><secondary-title><style face="normal" font="default" size="100%">FUNCTIONAL PLANT BIOLOGY</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">morphological convergence</style></keyword><keyword><style  face="normal" font="default" size="100%">photoprotection</style></keyword><keyword><style  face="normal" font="default" size="100%">physiological performance</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus</style></keyword><keyword><style  face="normal" font="default" size="100%">Summer aridity</style></keyword><keyword><style  face="normal" font="default" size="100%">water stress</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year></dates><publisher><style face="normal" font="default" size="100%">CSIRO PUBLISHING</style></publisher><pub-location><style face="normal" font="default" size="100%">150 OXFORD ST, PO BOX 1139, COLLINGWOOD, VICTORIA 3066, AUSTRALIA</style></pub-location><volume><style face="normal" font="default" size="100%">36</style></volume><pages><style face="normal" font="default" size="100%">453-462</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The ability of three Mediterranean oaks (Quercus coccifera L., Quercus ilex ssp. ballota (Desf.) Samp and Quercus suber L.) to cope with intense drought was investigated. Water stress reduced stomatal conductance and photosynthesis in these species. Drought-mediated changes in photosynthetic-related parameters allowed the characterisation of the specific photo-protective mechanisms. Specifically, Q. suber downregulated photosynthetic electron transport rates (ETR) closing PSII reaction centres (i.e. decreasing photochemical quenching) and through an antheraxanthin (A) + zeaxanthin (Z)-mediated diminished intrinsic PSII efficiency (Phi(exc.).). These changes were lower in Q. coccifera and Q. ilex ssp. ballota, which decreased further ETR photo-inactivating PSII centres (evidenced by their low predawn F(v)/F(m) ratios at high water stress). The predawn F(v)/F(m) ratio decreased in Q. coccifera largely due to F(m) decreases, whereas in Q. ilex ssp. ballota F(v)/F(m) decreases were due to F(0) increases, below -4 MPa. These F(v)/F(m) decreases were well correlated with increases in the A + Z photo-protective pigments. An analysis of dark respiration and photorespiration as alternative electron sinks under intense drought stress also revealed interspecific differences. The largest imbalance between electrons generated and consumed increased potentially oxidative damage in Q. suber. Subsequently, only Q. suber showed loss of chlorophyll, which is one of the main targets of oxidative damage. Data suggest that Q. coccifera and Q. ilex ssp. ballota seem more able than Q. suber to withstand highly xeric conditions. Therefore, our results question the consideration of Mediterranean evergreen oaks as a homogeneous physiological group.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">García-Plazaola, José Ignacio</style></author><author><style face="normal" font="default" size="100%">Esteban, Raquel</style></author><author><style face="normal" font="default" size="100%">Hormaetxe, Koldobika</style></author><author><style face="normal" font="default" size="100%">Fernández-Marín, Beatriz</style></author><author><style face="normal" font="default" size="100%">Becerril, José Maria</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Photoprotective responses of Mediterranean and Atlantic trees to the extreme heat-wave of summer 2003 in Southwestern Europe</style></title><secondary-title><style face="normal" font="default" size="100%">Trees</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">á summer 2003</style></keyword><keyword><style  face="normal" font="default" size="100%">antioxidants</style></keyword><keyword><style  face="normal" font="default" size="100%">antioxidants á heat-wave á</style></keyword><keyword><style  face="normal" font="default" size="100%">heat-wave</style></keyword><keyword><style  face="normal" font="default" size="100%">mediterranean species</style></keyword><keyword><style  face="normal" font="default" size="100%">mediterranean species á photoprotection</style></keyword><keyword><style  face="normal" font="default" size="100%">photoprotection</style></keyword><keyword><style  face="normal" font="default" size="100%">summer 2003</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year></dates><volume><style face="normal" font="default" size="100%">22</style></volume><pages><style face="normal" font="default" size="100%">385-392</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Summer 2003 was extremely hot in Europe. High light in combination with heat and drought exacerbates the generation of photo-oxidative stress. Under these conditions photoprotective responses can be critical for plant survival. Photoprotection was analysed in 2003 in several Mediterranean and Atlantic woody species. These data were compared with previous summers (1998, 1999 and 2001) to evaluate the potential acclimation for each species. A pattern of changes consisting on a decrease in chlorophyll, ascorbate and Fv/Fm and an increase in tocopherol, xanthophyll cycle pigments (VAZ) and deepoxidation index was regularly observed. Acclimation potential was measured by the use of the plasticity index for each parameter. Mediterranean species were more plastic than Atlantic ones. The latter were unable to increase antioxidant pools to the same extent or to downregulate the efﬁciency of light energy conversion. These results indicate that most Mediterranean species are able to perform an efﬁcient acclimation to heat stress, whilst Atlantic species will be more affected by climate warming.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">García-Plazaola, José Ignacio</style></author><author><style face="normal" font="default" size="100%">Esteban, Raquel</style></author><author><style face="normal" font="default" size="100%">Hormaetxe, Koldobika</style></author><author><style face="normal" font="default" size="100%">Fernández-Marín, Beatriz</style></author><author><style face="normal" font="default" size="100%">Becerril, José Maria</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Photoprotective responses of Mediterranean and Atlantic trees to the extreme heat-wave of summer 2003 in Southwestern Europe</style></title><secondary-title><style face="normal" font="default" size="100%">Trees</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">á summer 2003</style></keyword><keyword><style  face="normal" font="default" size="100%">antioxidants</style></keyword><keyword><style  face="normal" font="default" size="100%">antioxidants á heat-wave á</style></keyword><keyword><style  face="normal" font="default" size="100%">heat-wave</style></keyword><keyword><style  face="normal" font="default" size="100%">mediterranean species</style></keyword><keyword><style  face="normal" font="default" size="100%">mediterranean species á photoprotection</style></keyword><keyword><style  face="normal" font="default" size="100%">photoprotection</style></keyword><keyword><style  face="normal" font="default" size="100%">summer 2003</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2008///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://link.springer.com/10.1007/s00468-007-0199-yhttp://www.springerlink.com/index/10.1007/s00468-007-0199-y</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">22</style></volume><pages><style face="normal" font="default" size="100%">385 - 392</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Summer 2003 was extremely hot in Europe. High light in combination with heat and drought exacerbates the generation of photo-oxidative stress. Under these conditions photoprotective responses can be critical for plant survival. Photoprotection was analysed in 2003 in several Mediterranean and Atlantic woody species. These data were compared with previous summers (1998, 1999 and 2001) to evaluate the potential acclimation for each species. A pattern of changes consisting on a decrease in chlorophyll, ascorbate and Fv/Fm and an increase in tocopherol, xanthophyll cycle pigments (VAZ) and deepoxidation index was regularly observed. Acclimation potential was measured by the use of the plasticity index for each parameter. Mediterranean species were more plastic than Atlantic ones. The latter were unable to increase antioxidant pools to the same extent or to downregulate the efﬁciency of light energy conversion. These results indicate that most Mediterranean species are able to perform an efﬁcient acclimation to heat stress, whilst Atlantic species will be more affected by climate warming.</style></abstract><issue><style face="normal" font="default" size="100%">3</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Corcuera, L</style></author><author><style face="normal" font="default" size="100%">Morales, F</style></author><author><style face="normal" font="default" size="100%">Abadía, A</style></author><author><style face="normal" font="default" size="100%">Gil-Pelegrín, E</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">The effect of low temperatures on the photosynthetic apparatus of Quercus ilex subsp. ballota at its lower and upper altitudinal limits in the Iberian peninsula and during a single freezing-thawing cycle</style></title><secondary-title><style face="normal" font="default" size="100%">Trees</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">chlorophyll fluorescence</style></keyword><keyword><style  face="normal" font="default" size="100%">Holm oak</style></keyword><keyword><style  face="normal" font="default" size="100%">photochemical and non-photochemical quenching</style></keyword><keyword><style  face="normal" font="default" size="100%">photoprotection</style></keyword><keyword><style  face="normal" font="default" size="100%">photosystem ii efficiency</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2004</style></year></dates><volume><style face="normal" font="default" size="100%">19</style></volume><pages><style face="normal" font="default" size="100%">99-108</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We investigated the response of the photosynthetic apparatus during an episode of extreme low winter temperature in Quercus ilex subsp. ballota (Desf.) Samp., a typical Mediterranean evergreen species in the Iberian peninsula. Both plants in a woodland located at high altitude (1,177 m. a.s.l.) and potted plants obtained from acorns of the same populations grown at low altitude (225 m. a.s.l.) were analyzed. Net CO2 assimilation rate was negative and there was a marked decrease in photosystem II (PSII) efficiency during winter in leaves of the woodland population (high altitude individuals). These processes were accompanied by increases in nonphotochemical quenching (NPQ) and in the de-epoxidated carotenoids within the xanthophyll cycle, mechanisms aimed to dissipate excess energy. In addition, these deepoxidated carotenoids were largely preserved during the night. There was no chlorophyll bleaching during the winter, which suggests that leaves were not experiencing photoinhibitory damage. In fact, the net photosynthetic rate and the PSII efficiency recovered in spring. These changes were not observed, or were much more reduced, in individuals located at lower altitude after a few frosts. When the response to rapid temperature changes (from 20°C to −5°C and from −5°C to 20°C) was studied, it was found that the maximum potential PSII efficiency was fairly stable, ranging from 0.70 to 0.75. The rest of the photosynthetic parameters measured, actual and intrinsic PSII efficiency, photochemical and NPQ, responded immediately to the changes in temperature and, also, the recovery after cold events was practically immediate.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Corcuera, L.</style></author><author><style face="normal" font="default" size="100%">Morales, F.</style></author><author><style face="normal" font="default" size="100%">Abadia, A.</style></author><author><style face="normal" font="default" size="100%">GIL-PELEGRÍN, E.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">The effect of low temperatures on the photosynthetic apparatus of Quercus ilex subsp. ballota at its lower and upper altitudinal limits in the Iberian peninsula and during a single freezing-thawing cycle</style></title><secondary-title><style face="normal" font="default" size="100%">Trees</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">chlorophyll fluorescence</style></keyword><keyword><style  face="normal" font="default" size="100%">Holm oak</style></keyword><keyword><style  face="normal" font="default" size="100%">photochemical and non-photochemical quenching</style></keyword><keyword><style  face="normal" font="default" size="100%">photoprotection</style></keyword><keyword><style  face="normal" font="default" size="100%">photosystem ii efficiency</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2004</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2004///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.springerlink.com/index/10.1007/s00468-004-0368-1</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">19</style></volume><pages><style face="normal" font="default" size="100%">99 - 108</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We investigated the response of the photosynthetic apparatus during an episode of extreme low winter temperature in Quercus ilex subsp. ballota (Desf.) Samp., a typical Mediterranean evergreen species in the Iberian peninsula. Both plants in a woodland located at high altitude (1,177 m. a.s.l.) and potted plants obtained from acorns of the same populations grown at low altitude (225 m. a.s.l.) were analyzed. Net CO2 assimilation rate was negative and there was a marked decrease in photosystem II (PSII) efficiency during winter in leaves of the woodland population (high altitude individuals). These processes were accompanied by increases in nonphotochemical quenching (NPQ) and in the de-epoxidated carotenoids within the xanthophyll cycle, mechanisms aimed to dissipate excess energy. In addition, these deepoxidated carotenoids were largely preserved during the night. There was no chlorophyll bleaching during the winter, which suggests that leaves were not experiencing photoinhibitory damage. In fact, the net photosynthetic rate and the PSII efficiency recovered in spring. These changes were not observed, or were much more reduced, in individuals located at lower altitude after a few frosts. When the response to rapid temperature changes (from 20°C to −5°C and from −5°C to 20°C) was studied, it was found that the maximum potential PSII efficiency was fairly stable, ranging from 0.70 to 0.75. The rest of the photosynthetic parameters measured, actual and intrinsic PSII efficiency, photochemical and NPQ, responded immediately to the changes in temperature and, also, the recovery after cold events was practically immediate.</style></abstract><issue><style face="normal" font="default" size="100%">1</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Martínez-Ferri, E</style></author><author><style face="normal" font="default" size="100%">Manrique, E</style></author><author><style face="normal" font="default" size="100%">Valladares, F</style></author><author><style face="normal" font="default" size="100%">Balaguer, L</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Winter photoinhibition in the field involves different processes in four co-occurring Mediterranean tree species</style></title><secondary-title><style face="normal" font="default" size="100%">Tree Physiology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">chlorophyll</style></keyword><keyword><style  face="normal" font="default" size="100%">Chlorophyll: physiology</style></keyword><keyword><style  face="normal" font="default" size="100%">Juniperus</style></keyword><keyword><style  face="normal" font="default" size="100%">Juniperus: physiology</style></keyword><keyword><style  face="normal" font="default" size="100%">photoprotection</style></keyword><keyword><style  face="normal" font="default" size="100%">Pinus</style></keyword><keyword><style  face="normal" font="default" size="100%">Pinus: physiology</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Leaves</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Leaves: physiology</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus: physiology</style></keyword><keyword><style  face="normal" font="default" size="100%">Seasons</style></keyword><keyword><style  face="normal" font="default" size="100%">Sunlight</style></keyword><keyword><style  face="normal" font="default" size="100%">Trees</style></keyword><keyword><style  face="normal" font="default" size="100%">Trees: physiology</style></keyword><keyword><style  face="normal" font="default" size="100%">xanthophyll cycle</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2004</style></year></dates><volume><style face="normal" font="default" size="100%">24</style></volume><pages><style face="normal" font="default" size="100%">981-990</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Photoinhibition was examined in four co-occurring Mediterranean evergreen tree species during two consecutive winters. In response to low temperatures and saturating light, Juniperus phoenicea L., Pinus halepensis Mill., Quercus coccifera L. and Q. ilex ssp. ballota (Desf.) Samp. exhibited marked chronic photoinhibition, indicated by low predawn maximal photochemical efficiency of photosystem II (PSII) (Fv/Fm). Low Fv/Fm values were correlated with high concentrations of xanthophyll cycle components (VAZ) and with the maintenance of high concentrations of zeaxanthin overnight (DPSpd). In all species, however, chronic photoinhibition was enhanced as the winter progressed in the absence of changes in DPSpd, suggesting cumulative damage toward the end of winter.Photoinhibition differed among species: P. halepensis always displayed significantly higher Fv/Fm values; and Q. coccifera had the lowest Fv/Fm values, showing a high sensitivity to the combination of high light and low temperatures. Differences among species were not fully explained by differences in the xanthophyll pool or its de-epoxidation state. Chronic photoinhibition overlapped with a dynamic photoinhibition as shown by the low values of photochemical efficiency of the open reaction centers of PSII at midday. Winter photoprotective strategies differed among species and may involve photoprotective mechanisms in addition to those associated with xanthophylls. The observed species-specific differences matched results obtained for the same species in summer; however, comparison of the two seasons suggests that the higher VAZ concentration observed in winter has an additional structural photoprotective role.</style></abstract><accession-num><style face="normal" font="default" size="100%">15234895</style></accession-num><notes><style face="normal" font="default" size="100%">From Duplicate 2 (Winter photoinhibition in the field involves different processes in four co-occurring Mediterranean tree species - Martínez-Ferri, E; Manrique, E; Valladares, F; Balaguer, L)</style></notes><research-notes><style face="normal" font="default" size="100%">From Duplicate 2 (Winter photoinhibition in the field involves different processes in four co-occurring Mediterranean tree species - Martínez-Ferri, E; Manrique, E; Valladares, F; Balaguer, L)</style></research-notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Oliveira, G</style></author><author><style face="normal" font="default" size="100%">Penuelas, J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Comparative protective strategies of Cistus albidus and Quercus ilex facing photoinhibitory winter conditions</style></title><secondary-title><style face="normal" font="default" size="100%">Environmental and experimental botany</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">evergreen</style></keyword><keyword><style  face="normal" font="default" size="100%">leaf angle</style></keyword><keyword><style  face="normal" font="default" size="100%">manipulation</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean winter</style></keyword><keyword><style  face="normal" font="default" size="100%">photoprotection</style></keyword><keyword><style  face="normal" font="default" size="100%">semideciduous</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2002</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2002///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.sciencedirect.com/science/article/pii/S0098847202000035</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">47</style></volume><pages><style face="normal" font="default" size="100%">281 - 289</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The role of structural photoprotection under photoinhibitory winter conditions was evaluated in two Mediterranean woody species: Cistus albidus (semideciduous) and Quercus ilex (evergreen). Shoots were manipulated in order to modify the light load naturally received by the leaves throughout the cold season, and monitored for changes in maximum photochemical efﬁciency of PSII, phenology, and leaf morphology. Naturally steep leaves of C. albidus were restrained to a horizontal position, and compared with control leaves (naturally horizontal, or steeply inclined). Fully exposed leaves of Q. ilex were artiﬁcially protected through partial shading, and compared with control leaves (not shaded). During the cold season, the most exposed (either naturally or artiﬁcially) leaves were always more photoinhibited (had lower maximal photochemical efﬁciency of PSII) than the photoprotected ones. The differences disappeared at the beginning of spring. Winter photoinhibition was not more pronounced in older than in younger leaves of C. albidus, indicating that inclination rather than age affected their photochemical efﬁciency. Leaf chlorophyll contents were not signiﬁcantly affected by the manipulations. Leaf thickness decreased slightly in the least exposed shoots of the evergreen species, but no changes were detected in leaf morphological traits of the semideciduous one. The increased photoinhibitory pressure led only to slight and non-signiﬁcant changes in phenology and growth</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Morales, F</style></author><author><style face="normal" font="default" size="100%">Abadía, A</style></author><author><style face="normal" font="default" size="100%">Abadia, J</style></author><author><style face="normal" font="default" size="100%">Montserrat, G</style></author><author><style face="normal" font="default" size="100%">Gil-Pelegrín, E</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Trichomes and photosynthetic pigment composition changes: responses of Quercus ilex subsp. ballota (Desf.) Samp. and Quercus coccifera L. to Mediterranean stress conditions</style></title><secondary-title><style face="normal" font="default" size="100%">Trees</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">adaxial epidermis</style></keyword><keyword><style  face="normal" font="default" size="100%">photoprotection</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus</style></keyword><keyword><style  face="normal" font="default" size="100%">Trichomes</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2002</style></year></dates><volume><style face="normal" font="default" size="100%">16</style></volume><pages><style face="normal" font="default" size="100%">504-510</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Sun and shade leaves of two Mediterranean Quercus species, Quercus ilex subsp. ballota (Desf.) Samp. and Quercus coccifera L., were compared by measuring leaf optical properties, photosynthetic pigment composition and photosystem II efficiency. The presence of trichomes in the adaxial (upper) leaf surface of Q. ilex subsp. ballota seems to constitute an important morphological mechanism that allows this species to maintain a good photosystem II efficiency during the summer. Q. coccifera has almost no trichomes and seems instead to develop other physiological responses, including a smaller light-harvesting antenna size, higher concentrations of violaxanthin cycle pigments and a higher (zeaxanthin + antheraxanthin)/(violaxanthin + antheraxanthin + zeaxanthin) ratio. Q. coccifera was not able to maintain a good photosystem II efficiency up to the end of the summer. In Q. ilex subsp. ballota leaves, natural loss or mechanical removal of adaxial-face leaf trichomes induced short-term decreases in photosystem II efficiency. These changes were accompanied by deepoxidation of violaxanthin cycle pigments, suggesting that the absence of trichomes would trigger physiological responses in this species. Our data have revealed different patterns of response of Q. ilex subsp. ballota and Q. coccifera facing the stress conditions prevailing in the Mediterranean area.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Morales, F.</style></author><author><style face="normal" font="default" size="100%">Abadia, A.</style></author><author><style face="normal" font="default" size="100%">Abadía, J.</style></author><author><style face="normal" font="default" size="100%">Montserrat, G.</style></author><author><style face="normal" font="default" size="100%">GIL-PELEGRÍN, E.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Trichomes and photosynthetic pigment composition changes: responses of Quercus ilex subsp. ballota (Desf.) Samp. and Quercus coccifera L. to Mediterranean stress conditions</style></title><secondary-title><style face="normal" font="default" size="100%">Trees</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">adaxial epidermis</style></keyword><keyword><style  face="normal" font="default" size="100%">photoprotection</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus</style></keyword><keyword><style  face="normal" font="default" size="100%">Trichomes</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2002</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2002///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://link.springer.de/link/service/journals/00468/bibs/2016007/20160504.htm</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">16</style></volume><pages><style face="normal" font="default" size="100%">504 - 510</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Sun and shade leaves of two Mediterranean Quercus species, Quercus ilex subsp. ballota (Desf.) Samp. and Quercus coccifera L., were compared by measuring leaf optical properties, photosynthetic pigment composition and photosystem II efficiency. The presence of trichomes in the adaxial (upper) leaf surface of Q. ilex subsp. ballota seems to constitute an important morphological mechanism that allows this species to maintain a good photosystem II efficiency during the summer. Q. coccifera has almost no trichomes and seems instead to develop other physiological responses, including a smaller light-harvesting antenna size, higher concentrations of violaxanthin cycle pigments and a higher (zeaxanthin + antheraxanthin)/(violaxanthin + antheraxanthin + zeaxanthin) ratio. Q. coccifera was not able to maintain a good photosystem II efficiency up to the end of the summer. In Q. ilex subsp. ballota leaves, natural loss or mechanical removal of adaxial-face leaf trichomes induced short-term decreases in photosystem II efficiency. These changes were accompanied by deepoxidation of violaxanthin cycle pigments, suggesting that the absence of trichomes would trigger physiological responses in this species. Our data have revealed different patterns of response of Q. ilex subsp. ballota and Q. coccifera facing the stress conditions prevailing in the Mediterranean area.</style></abstract><issue><style face="normal" font="default" size="100%">7</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Llorens, L.</style></author><author><style face="normal" font="default" size="100%">Aranda, X.</style></author><author><style face="normal" font="default" size="100%">Abadia, A.</style></author><author><style face="normal" font="default" size="100%">Fleck, I.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Variations in Quercus ilex chloroplast pigment content during summer stress: involvement in photoprotection according to principal component analysis</style></title><secondary-title><style face="normal" font="default" size="100%">FUNCTIONAL PLANT BIOLOGY</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">6-epoxide</style></keyword><keyword><style  face="normal" font="default" size="100%">chlorophyll</style></keyword><keyword><style  face="normal" font="default" size="100%">lutein-5</style></keyword><keyword><style  face="normal" font="default" size="100%">photoprotection</style></keyword><keyword><style  face="normal" font="default" size="100%">Principal component analysis</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2002</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2002///</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">29</style></volume><pages><style face="normal" font="default" size="100%">81 - 88</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We examined chloroplast pigment variation in holm oak (Quercus ilex L.) leaves for two periods under two climatic conditions, at midday during summer. We compared variation between control (unburned) plants and plants burned the preceding summer, since post-fire resprouts show higher photosynthetic rates and lower thermal energy dissipation. Principal component (PC) analysis was performed on nine pigment-content variables for the two periods separately. Two PC factors (PC1 and PC2) explained 83 and 84% of the variance of the data for each period. In both periods, PC 1 was marked by positive loading of pigments associated with light absorption or structural function namely neoxanthin, lutein, beta-carotene, chlorophyll a, and chlorophyll b. These pigments were only affected by leaf age. In contrast, PC2 was marked by high loadings of xanthophyll-cycle pigments (associated with photoprotection), and lutein-5,6-epoxide. Leaf content of these pigments was affected by climatic conditions. In the situations considered in PC analysis (leaf types, periods), the lutein-5,6-epoxide content presented a variation pattern similar to that of violaxanthin, and was significantly correlated with thermal dissipation of excess energy (represented by non-photochemical quenching or NPQ). These results suggest a relationship of lutein and lutein-5,6-epoxide with photoprotection.</style></abstract><issue><style face="normal" font="default" size="100%">1</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;pub-location: 150 OXFORD ST, PO BOX 1139, COLLINGWOOD, VICTORIA 3066, AUSTRALIA&lt;br/&gt;publisher: C S I R O PUBLISHING</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">García-Plazaola, J. I.</style></author><author><style face="normal" font="default" size="100%">Artetxe, Unai</style></author><author><style face="normal" font="default" size="100%">BECERRIL, J. M.</style></author><author><style face="normal" font="default" size="100%">Garcı, Ignacio</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Diurnal changes in antioxidant and carotenoid composition in the Mediterranean schlerophyll tree Quercus ilex(L) during winter</style></title><secondary-title><style face="normal" font="default" size="100%">Plant Science</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Holm oak</style></keyword><keyword><style  face="normal" font="default" size="100%">low-temperature stress</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean evergreens</style></keyword><keyword><style  face="normal" font="default" size="100%">photoinhibition</style></keyword><keyword><style  face="normal" font="default" size="100%">photoprotection</style></keyword><keyword><style  face="normal" font="default" size="100%">xanthophyll cycle</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1999</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1999///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.sciencedirect.com/science/article/pii/S0168945299000345</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">143</style></volume><pages><style face="normal" font="default" size="100%">125 - 133</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Seasonal changes of pigment composition and antioxidant content were characterized in the Mediterranean evergreen holm oak (Quercus ilex L.). Higher contents of antioxidants and carotenoids, with a photoprotective role during winter, indicated that this period was highly stressful, so a study of diurnal changes in photosynthesis, pigments and carotenoids was conducted during January in sun and shade leaves. Sun and shade leaves were used to compare the effects due only to low temperature separate from those resulting from the interaction of light. During winter, a relatively high rate of CO2 ﬁxation on sun leaves represented an important sink for photosynthetic electrons contributing to the annual carbon balance of the plant. This high rate contrasted with a reduced Fv :Fm, even at predawn. This reduction was correlated with the accumulation of zeaxanthin at the expense of violaxanthin by de-epoxidation. Sun leaves were also protected by a higher concentration of antioxidants (ascorbate, glutathione and tocopherol) and carotenoids (except lutein epoxide). Ascorbate was 10–50-fold greater than the other antioxidants, indicating a central role in protection against photooxidative stress. Nevertheless those mechanisms were unable to avoid a loss of hydrophilic antioxidants (glutathione and ascorbate) and xanthophylls during the initial morning hours after dawn, indicating that the ﬁrst target of photooxidative damage was these molecules</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Garcia-Plazaola, J I</style></author><author><style face="normal" font="default" size="100%">Artetxe, Unai</style></author><author><style face="normal" font="default" size="100%">BECERRIL, J M</style></author><author><style face="normal" font="default" size="100%">Garcı, Ignacio</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Diurnal changes in antioxidant and carotenoid composition in the Mediterranean schlerophyll tree Quercus ilex(L) during winter</style></title><secondary-title><style face="normal" font="default" size="100%">Plant Science</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Holm oak</style></keyword><keyword><style  face="normal" font="default" size="100%">low-temperature stress</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean evergreens</style></keyword><keyword><style  face="normal" font="default" size="100%">photoinhibition</style></keyword><keyword><style  face="normal" font="default" size="100%">photoprotection</style></keyword><keyword><style  face="normal" font="default" size="100%">xanthophyll cycle</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1999</style></year></dates><volume><style face="normal" font="default" size="100%">143</style></volume><pages><style face="normal" font="default" size="100%">125-133</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Seasonal changes of pigment composition and antioxidant content were characterized in the Mediterranean evergreen holm oak (Quercus ilex L.). Higher contents of antioxidants and carotenoids, with a photoprotective role during winter, indicated that this period was highly stressful, so a study of diurnal changes in photosynthesis, pigments and carotenoids was conducted during January in sun and shade leaves. Sun and shade leaves were used to compare the effects due only to low temperature separate from those resulting from the interaction of light. During winter, a relatively high rate of CO2 ﬁxation on sun leaves represented an important sink for photosynthetic electrons contributing to the annual carbon balance of the plant. This high rate contrasted with a reduced Fv :Fm, even at predawn. This reduction was correlated with the accumulation of zeaxanthin at the expense of violaxanthin by de-epoxidation. Sun leaves were also protected by a higher concentration of antioxidants (ascorbate, glutathione and tocopherol) and carotenoids (except lutein epoxide). Ascorbate was 10–50-fold greater than the other antioxidants, indicating a central role in protection against photooxidative stress. Nevertheless those mechanisms were unable to avoid a loss of hydrophilic antioxidants (glutathione and ascorbate) and xanthophylls during the initial morning hours after dawn, indicating that the ﬁrst target of photooxidative damage was these molecules</style></abstract></record></records></xml>