<?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%">Fares, S</style></author><author><style face="normal" font="default" size="100%">Loreto, F</style></author><author><style face="normal" font="default" size="100%">Kleist, E</style></author><author><style face="normal" font="default" size="100%">Wildt, J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Stomatal uptake and stomatal deposition of ozone in isoprene and monoterpene emitting plants</style></title><secondary-title><style face="normal" font="default" size="100%">Plant Biology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">isoprene</style></keyword><keyword><style  face="normal" font="default" size="100%">Monoterpenes</style></keyword><keyword><style  face="normal" font="default" size="100%">Ozone uptake</style></keyword><keyword><style  face="normal" font="default" size="100%">photosynthesis</style></keyword><keyword><style  face="normal" font="default" size="100%">reaction chambers</style></keyword><keyword><style  face="normal" font="default" size="100%">Stomatal conductance</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year></dates><publisher><style face="normal" font="default" size="100%">Blackwell Publishing Ltd</style></publisher><volume><style face="normal" font="default" size="100%">10</style></volume><pages><style face="normal" font="default" size="100%">44-54</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Volatile isoprenoids were reported to protect plants against ozone. To understand whether this could be the result of a direct scavenging of ozone by these molecules, the stomatal and non-stomatal uptake of ozone was estimated in plants emitting isoprene or monoterpenes. Ozone uptake by holm oak (Quercus ilex, a monoterpene emitter) and black poplar (Populus nigra, an isoprene emitter) was studied in whole plant enclosures (continuously stirred tank reactors, CSTR). The ozone uptake by plants was estimated measuring ozone concentration at the inlet and outlet of the reactors, after correcting for the uptake of the enclosure materials. Destruction of ozone at the cuticle or at the plant stems was found to be negligible compared to the ozone uptake through the stomata. For both plant species, a relationship between stomatal conductance and ozone uptake was found. For the poplar, the measured ozone losses were explained by the uptake of ozone through the stomata only, and ozone destruction by gas phase reactions with isoprene was negligible. For the oak, gas phase reactions of ozone with the monoterpenes emitted by the plants contributed significantly to ozone destruction. This was confirmed by two different experiments showing a) that in cases of high stomatal conductance but under low CO2 concentration, a reduction of monoterpene emission was still associated with reduced O3 uptake; and b) that ozone losses due to the gas phase reactions only can be measured when using the exhaust from a plant chamber to determine the gas phase reactivity in an empty reaction chamber. Monoterpenes can therefore relevantly scavenge ozone at leaf level contributing to protection against ozone.</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%">Loreto, F</style></author><author><style face="normal" font="default" size="100%">Ciccioli, P</style></author><author><style face="normal" font="default" size="100%">Cecinato, A</style></author><author><style face="normal" font="default" size="100%">Brancaleoni, E</style></author><author><style face="normal" font="default" size="100%">Frattoni, M</style></author><author><style face="normal" font="default" size="100%">Fabozzi, C</style></author><author><style face="normal" font="default" size="100%">Tricoli, D</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Evidence of the photosynthetic origin of monoterpenes emitted by Quercus ilex L leaves by C-13 labeling</style></title><secondary-title><style face="normal" font="default" size="100%">PLANT PHYSIOLOGY</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">alpha-pinene</style></keyword><keyword><style  face="normal" font="default" size="100%">C-13 labeling</style></keyword><keyword><style  face="normal" font="default" size="100%">Emissions</style></keyword><keyword><style  face="normal" font="default" size="100%">isoprene</style></keyword><keyword><style  face="normal" font="default" size="100%">Monoterpenes</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus flex L.</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1996</style></year></dates><publisher><style face="normal" font="default" size="100%">AMER SOC PLANT PHYSIOLOGISTS</style></publisher><pub-location><style face="normal" font="default" size="100%">15501 MONONA DRIVE, ROCKVILLE, MD 20855</style></pub-location><volume><style face="normal" font="default" size="100%">110</style></volume><pages><style face="normal" font="default" size="100%">1317-1322</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The carbon of the four main monoterpenes emitted by Quercus flex L. leaves was completely labeled with C-13 after a 20-min feeding with 99% (CO2)-C-13. This labeling time course is comparable with the labeling time course of isoprene, the terpenoid emitted by other Quercus species and synthesized in leaf chloroplasts. It is also comparable with that of phosphoglyceric acid. Our experiment therefore provides evidence that monoterpenes emitted by Q. ilex are formed from photosynthesis intermediates and may share the same synthetic pathway with isoprene. By analyzing the rate and the distribution of labeling in the different fragments, we looked for evidence of differential carbon labeling in the alpha-pinene emitted. However, the labeling pattern was quite uniform in the different fragments, suggesting that the carbon skeleton of the emitted monoterpenes comes from a unique carbon source.</style></abstract><notes><style face="normal" font="default" size="100%">APS</style></notes><research-notes><style face="normal" font="default" size="100%">APS</style></research-notes></record></records></xml>