New Perspectives on CO₂, Temperature, and Light Effects on BVOC Emissions Using Online Measurements by PTR-MS and Cavity Ring-Down Spectroscopy

Abstract

Volatile organic compounds (VOC) play important roles in atmospheric chemistry, plant ecology, and physiology, and biogenic VOC (BVOC) emitted by plants is the largest VOC source. Our knowledge about how environmental drivers (e.g., carbon, light, and temperature) may regulate BVOC emissions is limited because they are often not controlled. We combined a greenhouse facility to manipulate atmospheric CO2 ([CO2]) with proton-transfer-reaction mass spectrometry (PTR-MS) and cavity ring-down spectroscopy to investigate the regulation of BVOC in Norway spruce. Our results indicate a direct relationship between [CO2] and methanol and acetone emissions, and their temperature and light dependencies, possibly related to substrate availability. The composition of monoterpenes stored in needles remained constant, but emissions of mono-(linalool) and sesquiterpenes (β-farnesene) increased at lower [CO2], with the effects being most pronounced at the highest air temperature. Pulse-labeling suggested an immediate incorporation of recently assimilated carbon into acetone, mono- and sesquiterpene emissions even under 50 ppm [CO2]. Our results provide new perspectives on CO2, temperature and light effects on BVOC emissions, in particular how they depend on stored pools and recent photosynthetic products. Future studies using smaller but more seedlings may allow sufficient replication to examine the physiological mechanisms behind the BVOC responses.

Effect of Drought on the Methylerythritol 4-Phosphate (MEP) Pathway in the Isoprene Emitting Conifer Picea glauca

“…Our experiment was conducted in August. Exposing Picea abies to a low atmospheric CO 2 concentration (50 ppm) also did not change the amount of monoterpenes stored in current year needles ( Huang et al, 2018 ).…”

Significant emissions of dimethyl sulfide and monoterpenes by big-leaf mahogany trees: discovery of a missing dimethyl sulfide source to the atmospheric environment

“…This is helpful as A net is a good proxy for the rate of photosynthesis and a recent 13 C-pulsed labeling study has shown that newly assimilated carbon can be emitted as monoterpenes within 1 h (Huang et al, 2018). Further, depending on whether the tree's growth is in the reproductive or vegetative phase (Huijser and Schmid, 2011), the assimilated carbon can be allocated differently, impacting the emitted BVOC flux. For example, one could expect that in the constitutive growth phase, emissions of BVOCs would be lower, whereas, in the reproductive phase, when flowering and fruiting occur, due to the important functional roles BVOCs play in attracting pollinators and for plant defense, there would be increased emissions of BVOCs (Peñuelas, 2003).…”

Flaming as part of aseptic technique increases CO2 (g) and decreases pH in freshwater culture media

“…We have demonstrated that flame sterilization of culture medium vessel openings can result in a significant decline in the pH of freshwater media due to the dissolution and hydration of CO 2 . This decline in pH has several implications, as optimal pH ranges for algal photosynthesis and growth are often narrow and well defined (Huang et al 2018). Moreover, under current climate scenarios, research into the effects of small pH shifts is common yet could be compromised by this observation.…”