<?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%">Song, W</style></author><author><style face="normal" font="default" size="100%">Staudt, M</style></author><author><style face="normal" font="default" size="100%">Bourgeois, I</style></author><author><style face="normal" font="default" size="100%">Williams, J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Laboratory and field measurements of enantiomeric monoterpene emissions as a function of chemotype, light and temperature</style></title><secondary-title><style face="normal" font="default" size="100%">BIOGEOSCIENCES</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Monoterpenes</style></keyword><keyword><style  face="normal" font="default" size="100%">Pinus halepensis Mill.</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex L.</style></keyword><keyword><style  face="normal" font="default" size="100%">Rosmarinus officinalis L.</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2014</style></year></dates><publisher><style face="normal" font="default" size="100%">COPERNICUS GESELLSCHAFT MBH</style></publisher><pub-location><style face="normal" font="default" size="100%">BAHNHOFSALLEE 1E, GOTTINGEN, 37081, GERMANY</style></pub-location><volume><style face="normal" font="default" size="100%">11</style></volume><pages><style face="normal" font="default" size="100%">1435-1447</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Plants emit significant amounts of monoterpenes into the earth's atmosphere, where they react rapidly to form a multitude of gas phase species and particles. Many monoterpenes exist in mirror-image forms or enantiomers. In this study the enantiomeric monoterpene profile for several representative plants (Quercus ilex L., Rosmarinus officinalis L., and Pinus halepensis Mill.) was investigated as a function of chemotype, light and temperature both in the laboratory and in the field. Analysis of enantiomeric monoterpenes from 19 Quercus ilex individuals from Southern France and Spain revealed four regiospecific chemotypes (genetically fixed emission patterns). In agreement with previous work, only Quercus ilex emissions increased strongly with light. However, for all three plant species no consistent enantiomeric variation was observed as a function of light, and the enantiomeric ratio of alpha-pinene was found to vary by less than 20% from 100 and 1000 mu mol m(-2) s(-1) PAR (photosynthetically active radiation). The rate of monoterpene emission increased with temperature from all three plant species, but little variation in the enantiomeric distribution of alpha-pinene was observed with temperature. There was more enantiomeric variability between individuals of the same species than could be induced by either light or temperature. Field measurements of alpha-pinene enantiomer mixing ratios in the air, taken at a Quercus ilex forest in Southern France, and several other previously reported field enantiomeric ratio diel cycle profiles are compared. All show smoothly varying diel cycles (some positive and some negative) even over changing wind directions. This is surprising in comparison with variations of enantiomeric emission patterns shown by individuals of the same species.</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><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%">Staudt, M</style></author><author><style face="normal" font="default" size="100%">Bertin, N</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Light and temperature dependence of the emission of cyclic and acyclic monoterpenes from holm oak (Quercus ilex L.) leaves</style></title><secondary-title><style face="normal" font="default" size="100%">Plant, Cell &amp; Environment</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">biogenic VOC emission</style></keyword><keyword><style  face="normal" font="default" size="100%">emission model</style></keyword><keyword><style  face="normal" font="default" size="100%">heat stress</style></keyword><keyword><style  face="normal" font="default" size="100%">Holm oak</style></keyword><keyword><style  face="normal" font="default" size="100%">Isoprenoids</style></keyword><keyword><style  face="normal" font="default" size="100%">light effect</style></keyword><keyword><style  face="normal" font="default" size="100%">Monoterpenes</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">temperature effect</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1998</style></year></dates><publisher><style face="normal" font="default" size="100%">Blackwell Publishing Ltd</style></publisher><volume><style face="normal" font="default" size="100%">21</style></volume><pages><style face="normal" font="default" size="100%">385-395</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">In a laboratory study, we investigated the monoterpene emissions from Quercus ilex, an evergreen sclerophyllous Mediterranean oak species whose emissions are light dependent. We examined the light and temperature responses of individual monoterpenes emitted from leaves under various conditions, the effect of heat stress on emissions, and the emission-onset during leaf development. Emission rate increased 10-fold during leaf growth, with slight changes in the composition. At 30 °C and saturating light, the monoterpene emission rate from mature leaves averaged 4·1 nmol m–2 s–1, of which α-pinene, sabinene and β-pinene accounted for 85%. The light dependence of emission was similar for all monoterpenes: it resembled the light saturation curve of CO2 assimilation, although monoterpene emission continued in the dark. Temperature dependence differed among emitted compounds: most of them exhibited an exponential increase up to 35 °C, a maximum at 42 °C, and a slight decline at higher temperatures. However, the two acyclic isomers cis-β-ocimene and trans-β-ocimene were hardly detected below 35 °C, but their emission rates increased above this temperature as the emission rates of other compounds fell, so that total emission of monoterpenes exponentially increased from 5 to 45 °C. The ratio between ocimene isomers and other compounds increased with both absolute temperature and time of heat exposure. The light dependence of emission was insensitive to the temperature at which it was measured, and vice versa the temperature dependence was insensitive to the light regime. The results demonstrated that none of the models currently applied to simulate isoprene or monoterpene emissions correctly predicts the short-term effects of light and temperature on Q. ilex emissions. The percentage of fixed carbon lost immediately as monoterpenes ranged between 0·1 and 6·0% depending on temperature, but rose up to 20% when leaves were continuously exposed to temperatures between 40 and 45 °C.</style></abstract></record></records></xml>