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| Titel |
Monoterpene and sesquiterpene emissions from Quercus coccifera exhibit interacting responses to light and temperature |
| VerfasserIn |
M. Staudt, L. Lhoutellier |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 8, no. 9 ; Nr. 8, no. 9 (2011-09-28), S.2757-2771 |
| Datensatznummer |
250006134
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| Publikation (Nr.) |
 copernicus.org/bg-8-2757-2011.pdf |
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| Zusammenfassung |
| Light and temperature are known to be the most important environmental
factors controlling biogenic volatile organic compound (BVOC) emissions from
plants, but little is known about their interdependencies especially for
BVOCs other than isoprene. We studied light responses at different
temperatures and temperature responses at different light levels of foliar
BVOC emissions, photosynthesis and chlorophyll fluorescence on Quercus coccifera, an
evergreen oak widespread in Mediterranean shrublands. More than 50 BVOCs
were detected in the emissions from Q. coccifera leaves most of them being isoprenoids
plus a few green leaf volatiles (GLVs). Under standard conditions
non-oxygenated monoterpenes (MT-hc) accounted for about 90% of the total
BVOC release (mean ± SD: 738 ± 378 ng m−2 projected leaf area s−1
or 13.1 ± 6.9 μg g−1 leaf dry weight h−1) and
oxygenated monoterpenes (MT-ox) and sesquiterpenes (SQTs) accounted for the
rest in about equal proportions. Except GLVs, emissions of all BVOCs
responded positively to light and temperature. The light responses of MT and
SQT emissions resembled that of CO2-assimilation and were little
influenced by the assay temperature: at high assay temperature, MT-hc
emissions saturated at lower light levels than at standard assay temperature
and tended even to decrease in the highest light range. The emission
responses to temperature showed mostly Arrhenius-type response curves, whose
shapes in the high temperature range were clearly affected by the assay
light level and were markedly different between isoprenoid classes: at
non-saturating light, all isoprenoids showed a similar temperature optimum
(~43 °C), but, at higher temperatures, MT-hc emissions decreased
faster than MT-ox and SQT emissions. At saturating light, MT-hc emissions
peaked around 37 °C and rapidly dropped at higher temperatures, whereas
MT-ox and SQT emissions strongly increased between 40 and 50 °C
accompanied by a burst of GLVs. In all experiments, decreases of MT-hc
emissions under high temperatures were correlated with decreases in
CO2-assimilation and/or photosynthetic electron transport. We conclude
that light and temperature can have interactive short-term effects on the
quantity and quality of BVOC emissions from Q. coccifera through substrate limitations
of MT biosynthesis occurring at temperatures supraoptimal for photosynthetic
processes that are exacerbated by oxidative stress and membrane damages.
Such interactive effects are likely to occur frequently during hot and dry
summers and simulations made in this work showed that they may have
important consequences for emission predictions. |
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