<?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%">Baquedano, F. J.</style></author><author><style face="normal" font="default" size="100%">Castillo, F. J.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Comparative ecophysiological effects of drought on seedlings of the Mediterranean water-saver Pinus halepensis and water-spenders Quercus coccifera and Quercus ilex</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%">antioxidant activity</style></keyword><keyword><style  face="normal" font="default" size="100%">chlorophyll fluorescence</style></keyword><keyword><style  face="normal" font="default" size="100%">gas exchange and water potential</style></keyword><keyword><style  face="normal" font="default" size="100%">morphological parameters</style></keyword><keyword><style  face="normal" font="default" size="100%">pigments</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2006</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2006///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.springerlink.com/index/10.1007/s00468-006-0084-0</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">20</style></volume><pages><style face="normal" font="default" size="100%">689 - 700</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Ecophysiological and structural traits of seedlings of the water-saver Pinus halepensis and the water-spenders Quercus coccifera and Q. ilex were studied in response to water stress under greenhouse conditions. Water deﬁcit reduced stomatal conductance (gs ) and, as a consequence, both net CO2 assimilation (A) and transpiration rate (E) were also reduced. Water stress also emphasized midday downregulation of the photochemical efﬁciency (dynamic photoinhibition) reducing quantum yield of noncyclic electron transport (PSII ), photochemical quenching (qP) and photochemical efﬁciency of the open reaction centres of PSII (F v /F m) and involved an increase of thermal dissipation of excess energy. However, water stress not only induced dynamic photoinhibition but also brought a reduction in Fv/Fm (chronic photoinhibition). Despite the water-saving strategy ofP. halepensisthat limited net CO2 assimilation, this species showed a higher photochemical efﬁciency and lower photoinhibition than Quercusspecies. This was not the result of a different photochemical quenching but was linked to a higher value of F v /F m, indicating a less severe photo-inactivation of PSII. Water stress resulted in a loss of pigment content and in an increase of the carotenoids/chlorophyll ratio, antioxidant capacity and the biomass rate allocated to roots as opposed to that assigned to leaves. P. halepensis showed a lower photoinhibition and antioxidant activity than Quercus species due to its lower pigment content and higher proportion of carotenoids allowing P. halepensis to use, in a more effective way, the lesser excess energy absorbed.</style></abstract><issue><style face="normal" font="default" size="100%">6</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%">García-Plazaola, J. I.</style></author><author><style face="normal" font="default" size="100%">FARIA, T.</style></author><author><style face="normal" font="default" size="100%">Abadía, J.</style></author><author><style face="normal" font="default" size="100%">Chaves, M. M.</style></author><author><style face="normal" font="default" size="100%">Pereira, J. S.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Seasonal changes in xanthophyll composition and photosynthesis of cork oak (Quercus suber L.) leaves under mediterranean climate</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Experimental Botany</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%">pigments</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber</style></keyword><keyword><style  face="normal" font="default" size="100%">thermal dissipation</style></keyword><keyword><style  face="normal" font="default" size="100%">xanthophylls</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1997</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1997///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://jxb.oxfordjournals.org/content/48/9/1667.abstract</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">48</style></volume><pages><style face="normal" font="default" size="100%">1667 - 1674</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Seasonal changes in pigment composition of sun and shade leaves of cork oak (Quercus suber) were studied under field conditions in Portugal. Expanding leaves showed a high concentration of xanthophyll cycle components, violaxanthin, antheraxanthin and zeaxanthin. The pool of violaxanthin plus antheraxanthin plus zeaxanthin (V+A+Z) varied greatly between the seasons, being higher at the end of summer and in winter when photosynthesis was limited by water stress and cold, respectively. The size of V+A+Z pool was associated to synthesis of zeaxanthin in response to an excess of light. In sun leaves, midday A+Z relative content was positively correlated with the V+A+Z pool, whereas in shade leaves A+Z decreased with leaf ageing. In both leaf types A+Z was positively correlated with the non-photochemical quenching (NPQ) of chlorophyll a fluorescence. However, in winter NPQ did not change significantly throughout the day, whereas the (A+Z)/(V+A+Z) increased following the typical daily trend observed in other seasons.</style></abstract><issue><style face="normal" font="default" size="100%">9</style></issue><notes><style face="normal" font="default" size="100%">10.1093/jxb/48.9.166710.1093/jxb/48.9.1667</style></notes></record></records></xml>