biogenic volatile organic compound and respiratory co2 emissions after 13c-labeling online tracing of c translocation dynamics in poplar plants生物挥发性有机化合物和呼吸二氧化碳排放后13 c-labeling在线跟踪c易位动力学杨树植物.pdf

Biogenic Volatile Organic Compound and Respiratory CO2 Emissions after 13C-Labeling: Online Tracing of C Translocation Dynamics in Poplar Plants ¤a ¤a ¨ ¤b ¨ ¤a Andrea Ghirardo , Jessica Gutknecht, Ina Zimmer , Nicolas Bruggemann , Jorg-Peter Schnitzler* Karlsruhe Institute of Technology, Institute for Meteorology and Climate Research, Garmisch-Partenkirchen, Germany Abstract Background: Globally plants are the primary sink of atmospheric CO , but are also the major contributor of a large spectrum 2 of atmospheric reactive hydrocarbons such as terpenes (e.g. isoprene) and other biogenic volatile organic compounds (BVOC). The prediction of plant carbon (C) uptake and atmospheric oxidation capacity are crucial to define the trajectory and consequences of global environmental changes. To achieve this, the biosynthesis of BVOC and the dynamics of C allocation and translocation in both plants and ecosystems are important. Methodology: We combined tunable diode laser absorption spectrometry (TDLAS) and proton transfer reaction mass spectrometry (PTR-MS) for studying isoprene biosynthesis and following C fluxes within grey poplar (Populus x canescens) saplings. This was achieved by feeding either 13CO2 to leaves or 13C-glucose to shoots via xylem uptake. The translocation of 13CO2 from the source to other plant parts could be traced by 13C-labeled isoprene and respiratory 13CO2 emission. Principal Finding: In intact plants, assimilated 13CO2 was rapidly translocated via the phloem to the roots within 1 hour, with an average phloem transport velocity of 20.3 62.5