Jardine Kolby J, Zorzanelli Raquel F, Gimenez Bruno O, Robles Emily, de Oliveira Piva Luani Rosa
Earth and Environmental Science Area, Lawrence Berkeley National Laboratory, One Cyclotron Rd, building 84-155, Berkeley, CA 94720, USA.
National Institute for Amazon Research, Department of Forest Management, Ave. Andre Araujo 2936, Manaus, AM 69.080-97, Brazil.
MethodsX. 2020 Apr 15;7:100880. doi: 10.1016/j.mex.2020.100880. eCollection 2020.
Understanding how plant carbon metabolism responds to environmental variables such as light is central to understanding ecosystem carbon cycling and the production of food, biofuels, and biomaterials. Here, we couple a portable leaf photosynthesis system to an autosampler for volatile organic compounds (VOCs) to enable field observations of net photosynthesis simultaneously with emissions of VOCs as a function of light. Following sample collection, VOCs are analyzed using automated thermal desorption-gas chromatograph-mass spectrometry (TD-GC-MS). An example is presented from a banana plant in the central Amazon with a focus on the response of photosynthesis and the emissions of eight individual monoterpenes to light intensity. Our observations reveal that banana leaf emissions represent a 1.1 +/- 0.1% loss of photosynthesis by carbon. Monoterpene emissions from banana are dominated by trans-β-ocimene, which accounts for up to 57% of total monoterpene emissions at high light. We conclude that the developed system is ideal for the identification and quantification of VOC emissions from leaves in parallel with CO2 and water fluxes.The system therefore permits the analysis of biological and environmental sensitivities of carbon metabolism in leaves in remote field locations, resulting in the emission of hydrocarbons to the atmosphere.•A field-portable system is developed for the identification and quantification of VOCs from leaves in parallel with leaf physiological measurements including photosynthesis and transpiration.•The system will enable the characterization of carbon and energy allocation to the biosynthesis and emission of VOCs linked with photosynthesis (e.g. isoprene and monoterpenes) and their biological and environmental sensitivities (e.g. light, temperature, CO).•Allow the development of more accurate mechanistic global VOC emission models linked with photosynthesis, improving our ability to predict how forests will respond to climate change. It is our hope that the presented system will contribute with critical data towards these goals across Earth's diverse tropical forests.
了解植物碳代谢如何响应光照等环境变量，对于理解生态系统碳循环以及食物、生物燃料和生物材料的生产至关重要。在此，我们将便携式叶片光合作用系统与挥发性有机化合物（VOCs）自动采样器相结合，以便在野外同时观测净光合作用以及VOCs排放随光照的变化情况。样品采集后，使用自动热解吸-气相色谱-质谱联用仪（TD-GC-MS）分析VOCs。文中给出了一个来自亚马逊中部香蕉植株的示例，重点关注光合作用的响应以及8种单萜类化合物的排放对光照强度的影响。我们的观测结果表明，香蕉叶排放的碳占光合作用损失的1.1±0.1%。香蕉的单萜类化合物排放以反式-β-罗勒烯为主，在高光强下，其占单萜类化合物总排放量的比例高达57%。我们得出结论，所开发的系统非常适合并行识别和量化叶片中的VOCs排放以及二氧化碳和水分通量。因此，该系统能够分析偏远野外地区叶片碳代谢的生物和环境敏感性，从而导致碳氢化合物向大气排放。
•开发了一种野外便携式系统，用于并行识别和量化叶片中的VOCs，并进行包括光合作用和蒸腾作用在内的叶片生理测量。
•该系统将能够表征与光合作用相关的VOCs（如异戊二烯和单萜类化合物）生物合成和排放的碳和能量分配情况，以及它们的生物和环境敏感性（如光照、温度、二氧化碳）。
•有助于开发与光合作用相关的更准确的全球VOC排放机制模型，提高我们预测森林对气候变化响应的能力。我们希望所展示的系统将为地球不同热带森林实现这些目标提供关键数据。
