Article

Increase in isoprene and monoterpene emissions after re-watering of droughted Quercus ilex seedlings

Biologia Plantarum (Impact Factor: 1.69). 01/2009; 53(2):351-354. DOI: 10.1007/s10535-009-0065-4

ABSTRACT We followed the diurnal cycles of isoprenoid emissions from Quercus ilex seedlings under drought and after re-watering. We found that Quercus ilex, generally considered a non-isoprene emitter, also emitted isoprene although at low rates. The emission rates of isoprene
reached 0.37 ± 0.02 nmol m−2 s−1 in controls, 0.15 ± 0.03 nmol m−2 s−1 under drought and 0.35 ± 0.04 nmol m−2 s−1 after re-watering, while emission rates of monoterpenes reached 11.0 ± 3.0, 7.0 ± 1.0 and 23.0 ± 5.0 nmol m−2 s−1, respectively. Emission rates recovered faster after re-watering than photosynthetic rate and followed diurnal changes in
irradiance in controls and under drought, but in leaf temperature after re-watering.

1 Bookmark
 · 
76 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Plant-generated volatile organic compounds (BVOCs) play key roles in large-scale atmospheric processes and serve the plants as important defense and signal molecules. The main emphasis in quantitative BVOC studies has been on constitutive emissions of isoprene and specific monoterpene species that are present in only certain emitting plant species. However, environmental and biotic stresses can induce emissions of an array of organic compounds in any plant species, whereas the magnitude of emissions induced by given stress depends on stress tolerance, timing, duration and severity (mild versus strong) of the stress. The main view put forward in this review is that quantitative understanding of stress effects is the key for constructing realistic models of both constitutive and induced BVOC emissions.
    Trends in Plant Science 12/2009; 15(3):145-53. · 11.81 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Atmospheric volatile organic compounds (VOCs) are involved in ozone and aerosol generation, thus having implications for air quality and climate. VOCs and their emissions by vegetation also have important ecological roles as they can protect plants from stresses and act as communication cues between plants and between plants and animals. In spite of these key environmental and biological roles, the reports on seasonal and daily VOC mixing ratios in the literature for Mediterranean natural environments are scarce. We conducted seasonal (winter and summer) measurements of VOC mixing ratios in an elevated (720 m a.s.l.) holm oak Mediterranean forest site near the metropolitan area of Barcelona (NE Iberian peninsula). Methanol was the most abundant compound among all the VOCs measured in both seasons. While aromatic VOCs showed almost no seasonal variability, short-chain oxygenated VOCs presented higher mixing ratios in summer, presumably due to greater emission by vegetation and increased photochemistry, both enhanced by the high temperatures and solar radiation in summer. Isoprenoid VOCs showed the biggest seasonal change in mixing ratios: they increased by one order of magnitude in summer, as a result of the vegetation's greater physiological activity and emission rates. The maximum diurnal concentrations of ozone increased in summer too, most likely due to more intense photochemical activity and the higher levels of VOCs in the air. The daily variation of VOC mixing ratios was mainly governed by the wind regime of the mountain, as the majority of the VOC species analyzed followed a very similar diel cycle. Mountain and sea breezes that develop after sunrise advect polluted air masses to the mountain. These polluted air masses had previously passed over the urban and industrial areas surrounding the Barcelona metropolitan area, where they were enriched in NOx and in VOCs of biotic and abiotic origin. Moreover, these polluted air masses receive additional biogenic VOCs emitted in the local valley by the vegetation, thus enhancing O3 formation in this forested site. The only VOC species that showed a somewhat different daily pattern were monoterpenes because of their local biogenic emission. Isoprene also followed in part the daily pattern of monoterpenes, but only in summer when its biotic sources were stronger. The increase by one order of magnitude in the concentrations of these volatile isoprenoids highlights the importance of local biogenic summer emissions in these Mediterranean forested areas which also receive polluted air masses from nearby or distant anthropic sources.
    ATMOSPHERIC CHEMISTRY AND PHYSICS 01/2011; 11(7):20389-20431. · 5.51 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This study offers new insight and data in support of the “opportunist hypothesis”, which suggests that there might be a relationship between carotenoid and volatile isoprenoid production. Five species of volatile isoprenoid-emitting plants (Eucalyptus globulus, Eucalyptus gunnii, Mucuna pruriens, Lycopersicon esculentum and Quercus ilex) were exposed to a range of imposed and natural stress conditions over a period of a few weeks in order to generate different levels of isoprenoid production potential. Volatile isoprenoid emission potentials and carotenoid concentrations were measured in all species, and dimethylallyl diphosphate (DMAPP) concentrations were measured in E. globulus, E. gunnii, M. pruriens and L. esculentum. Generally, instantaneously emitted isoprenoid emission potentials were positively correlated with carotenoid concentrations, and were negatively correlated with DMAPP concentrations. In contrast, emission potentials of monoterpenes stored in tissue pools were negatively correlated with carotenoid concentrations, and positively correlated with DMAPP concentrations. Our results support the possibility of a link (either direct, e.g. via substrate availability, or indirect, e.g. via complementary functionality) between emission potential of the volatile isoprenoid compounds studied here, and carotenoid synthesis at time scales of days to weeks.
    Acta Physiologiae Plantarum 11/2013; · 1.31 Impact Factor

Full-text (2 Sources)

View
36 Downloads
Available from
May 31, 2014