| Title: | Monoterpene 'thermometer' of tropical forest-atmosphere response to climate warming |
| Author(s): | Jardine KJ; Jardine AB; Holm JA; Lombardozzi DL; Negron-Juarez RI; Martin ST; Beller HR; Gimenez BO; Higuchi N; Chambers JQ; |
| Address: | "Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, 94720, Berkeley, CA, USA. National Institute for Amazon Research (INPA), 69060-001, Manaus, Amazonas, Brazil. Climate and Global Dynamics Laboratory, National Center for Atmospheric Research, 80307, Boulder, CO, USA. Harvard University, School of Engineering and Applied Sciences, 02138, Cambridge, MA, USA. Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, 94068, Emeryville, CA, USA. Department of Geography, University of California, 94720, Berkeley, CA, USA" |
| ISSN/ISBN: | 1365-3040 (Electronic) 0140-7791 (Linking) |
| Abstract: | "Tropical forests absorb large amounts of atmospheric CO(2) through photosynthesis but elevated temperatures suppress this absorption and promote monoterpene emissions. Using (13) CO(2) labeling, here we show that monoterpene emissions from tropical leaves derive from recent photosynthesis and demonstrate distinct temperature optima for five groups (Groups 1-5), potentially corresponding to different enzymatic temperature-dependent reaction mechanisms within beta-ocimene synthases. As diurnal and seasonal leaf temperatures increased during the Amazonian 2015 El Nino event, leaf and landscape monoterpene emissions showed strong linear enrichments of beta-ocimenes (+4.4% degrees C(-1) ) at the expense of other monoterpene isomers. The observed inverse temperature response of alpha-pinene (-0.8% degrees C(-1) ), typically assumed to be the dominant monoterpene with moderate reactivity, was not accurately simulated by current global emission models. Given that beta-ocimenes are highly reactive with respect to both atmospheric and biological oxidants, the results suggest that highly reactive beta-ocimenes may play important roles in the thermotolerance of photosynthesis by functioning as effective antioxidants within plants and as efficient atmospheric precursors of secondary organic aerosols. Thus, monoterpene composition may represent a new sensitive 'thermometer' of leaf oxidative stress and atmospheric reactivity, and therefore a new tool in future studies of warming impacts on tropical biosphere-atmosphere carbon-cycle feedbacks" |
| Keywords: | *Atmosphere Carbon/metabolism Carbon Dioxide/metabolism Carbon Isotopes Circadian Rhythm/physiology *Climate Change El Nino-Southern Oscillation *Forests Monoterpenes/*analysis Plant Leaves/physiology Seasons *Temperature *Tropical Climate Volatile Organi; |
| Notes: | "MedlineJardine, Kolby J Jardine, Angela B Holm, Jennifer A Lombardozzi, Danica L Negron-Juarez, Robinson I Martin, Scot T Beller, Harry R Gimenez, Bruno O Higuchi, Niro Chambers, Jeffrey Q eng Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. 2016/12/13 Plant Cell Environ. 2017 Mar; 40(3):441-452. doi: 10.1111/pce.12879. Epub 2017 Jan 27" |
