| Title: | Bidirectional Flux of Methyl Vinyl Ketone and Methacrolein in Trees with Different Isoprenoid Emission under Realistic Ambient Concentrations |
| Author(s): | Fares S; Paoletti E; Loreto F; Brilli F; |
| Address: | "daggerCouncil for Agricultural Research and Economics-Research Center for the Soil-Plant System, Rome 00184, Italy. double daggerNational Research Council, Institute for Sustainable Plant Protection (IPSP), Firenze 1-50019, Italy. section signNational Research Council, Department of Biology, Agriculture and Food Science (DISBA), Rome 7-00185, Italy. parallelNational Research Council, Institute of Agro-Environmental and Forest Biology (IBAF), Rome 7-00185, Italy" |
| ISSN/ISBN: | 1520-5851 (Electronic) 0013-936X (Linking) |
| Abstract: | "Methyl vinyl ketone (MVK) and methacrolein (MAC) are key oxidation products (iox) of isoprene, the most abundant volatile organic compound (VOC) emitted by vascular plants in the atmosphere. Increasing attention has been dedicated to iox, as they are involved in the photochemical cycles ultimately leading to ozone (O3) and particle formation. However, the capacity of plants to exchange iox under low and realistic ambient concentrations of iox needs to be assessed. We hypothesized that a foliar uptake of iox exists even under realistic concentrations of iox. We tested the capacity of iox exchange in trees constitutively emitting isoprene (Populus nigra) or monoterpenes (Quercus ilex), or that do not emit isoprenoids (Paulownia imperialis). Laboratory experiments were carried out at the leaf level using enclosures under controlled environmental factors and manipulating isoprene and reactive oxygen species (ROS) production by using the isoprene specific inhibitor fosmidomycin, acute O3 exposure (300 ppbv for 4 h), and dark conditions. We also tested whether stress conditions inducing accumulation of ROS significantly enhance iox formation in the leaf, and their emission. Our results show a negligible level of constitutive iox emission in unstressed plants, and in plants treated with high O3. The uptake of iox increased linearly with exposure to increasing concentrations of ambient iox (from 0 to 6 ppbv of a 1:1 = MVK/MAC mixture) in all the investigated species, indicating iox fast removal and low compensation point in unstressed and stressed conditions. Plant capacity to take up iox should be included in global models that integrate estimates of iox formation, emission, and photochemical reactions in the atmosphere" |
| Keywords: | Acrolein/*analogs & derivatives/analysis Butanones/*analysis Oxidation-Reduction Populus/chemistry Quercus/chemistry Terpenes/*analysis Trees/*chemistry Volatile Organic Compounds/analysis; |
| Notes: | "MedlineFares, Silvano Paoletti, Elena Loreto, Francesco Brilli, Federico eng Research Support, Non-U.S. Gov't 2015/06/02 Environ Sci Technol. 2015 Jul 7; 49(13):7735-42. doi: 10.1021/acs.est.5b00673. Epub 2015 Jun 11" |
