| Title: | Rapid conversion of isoprene photooxidation products in terrestrial plants |
| Author(s): | Canaval E; Millet DB; Zimmer I; Nosenko T; Georgii E; Partoll EM; Fischer L; Alwe HD; Kulmala M; Karl T; Schnitzler JP; Hansel A; |
| Address: | "Department of Ion Physics and Applied Physics, University of Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria. Department of Soil, Water and Climate, University of Minnesota, 439 Borlaug Hall, St. Paul, MN, USA. Research Unit Environmental Simulation (EUS), Institute of Biochemical Plant Pathology, Helmholtz Zentrum Munchen, Ingolstadter Landstrasse 1, 85764 Neuherberg, Germany. Institute of Biochemical Plant Pathology, Helmholtz Zentrum Munchen, Ingolstadter Landstrasse 1, 85764 Neuherberg, Germany. Institute for Atmospheric and Earth System Research (INAR)/Physics, University of Helsinki, Gustaf Hallstromin katu 2, 00014 Helsinki, Finland. Department of Atmospheric and Cryospheric Sciences, University of Innsbruck, Innrain 52f, 6020 Innsbruck, Austria" |
| DOI: | 10.1038/s43247-020-00041-2 |
| ISSN/ISBN: | 2662-4435 (Electronic) 2662-4435 (Linking) |
| Abstract: | "Isoprene is emitted from the biosphere into the atmosphere, and may strengthen the defense mechanisms of plants against oxidative and thermal stress. Once in the atmosphere, isoprene is rapidly oxidized, either to isoprene-hydroxy-hydroperoxides (ISOPOOH) at low levels of nitrogen oxides, or to methyl vinyl ketone (MVK) and methacrolein at high levels. Here we combine uptake rates and deposition velocities that we obtained in laboratory experiments with observations in natural forests to show that 1,2-ISOPOOH deposits rapidly into poplar leaves. There, it is converted first to cytotoxic MVK and then most probably through alkenal/ one oxidoreductase (AOR) to less toxic methyl ethyl ketone (MEK). This detoxification process is potentially significant globally because AOR enzymes are ubiquitous in terrestrial plants. Our simulations with a global chemistry-transport model suggest that around 6.5 Tg yr(-) of MEK are re-emitted to the atmosphere. This is the single largest MEK source presently known, and recycles 1.5% of the original isoprene flux. Eddy covariance flux measurements of isoprene and MEK over different forest ecosystems confirm that MEK emissions can reach 1-2% those of isoprene. We suggest that detoxification processes in plants are one of the most important sources of oxidized volatile organic compounds in the atmosphere" |
| Notes: | "PubMed-not-MEDLINECanaval, Eva Millet, Dylan B Zimmer, Ina Nosenko, Tetyana Georgii, Elisabeth Partoll, Eva Maria Fischer, Lukas Alwe, Hariprasad D Kulmala, Markku Karl, Thomas Schnitzler, Jorg-Peter Hansel, Armin eng NNX14AP89G/NASA/NASA/ England 2021/02/23 Commun Earth Environ. 2020; 1:44. doi: 10.1038/s43247-020-00041-2. Epub 2020 Nov 4" |
