« Previous AbstractPerformance characteristics and applications of a proton transfer reaction-mass spectrometer for measuring volatile organic compounds in ambient air    Next Abstract"RAM2, an essential gene of yeast, and RAM1 encode the two polypeptide components of the farnesyltransferase that prenylates a-factor and Ras proteins" »

Tree Physiol

Title:		Online analysis of volatile organic compound emissions from Sitka spruce (Picea sitchensis)
Author(s):		Hayward S; Tani A; Owen SM; Hewitt CN;
Address:		"Institute of Environmental and Natural Sciences, Lancaster University, Lancaster, LA1 4YQ, U.K"
Journal Title:		Tree Physiol
Year:		2004
Volume:		24
Issue:		7
Page Number:		721 - 728
DOI:		10.1093/treephys/24.7.721
ISSN/ISBN:		0829-318X (Print) 0829-318X (Linking)
Abstract:		"Volatile organic compound (VOC) emissions from Sitka spruce (Picea sitchensis Bong.) growing in a range of controlled light and temperature regimes were monitored online with a proton transfer reaction-mass spectrometer (PTR-MS) operating at a temporal resolution of approximately 1 min. Isoprene emissions accounted for an average of more than 70% of measured VOCs and up to 3.5% of assimilated carbon. Emission rates (E) for isoprene correlated closely with photosynthetic photon flux (PPF) and temperature, showing saturation at a PPF of between 300 and 400 micromol m(-2) s(-1) and a maximum between 35 and 38 degrees C. Under standard conditions of 30 degrees C and 1000 micromol m(-2) s(-1) PPF, the mean isoprene E was 13 microg gdm(-1) h(-1), considerably higher than previously observed in this species. Mean E for acetaldehyde, methanol and monoterpenes at 30 degrees C were 0.37, 0.78 and 2.97 microg gdm(-1) h(-1), respectively. In response to a sudden light to dark transition, isoprene E decreased exponentially by > 98% over about 3 h; however, during the first 7 min, this otherwise steady decay was temporarily but immediately depressed to approximately 40% of the pre-darkness rate, before rallying during the following 7 min to rejoin the general downward trajectory of the exponential decay. The sudden sharp fall in isoprene E was mirrored by a burst in acetaldehyde E. The acetaldehyde E maximum coincided with the isoprene E minimum (7 min post-illumination), and ceased when isoprene emissions resumed their exponential decay. The causes of, and linkages between, these phenomena were investigated"
Keywords:		Acetaldehyde/metabolism Butadienes/metabolism Hemiterpenes/metabolism Light Mass Spectrometry Methanol/metabolism Monoterpenes/metabolism Pentanes/metabolism Picea/*physiology Temperature Trees/*physiology;
Notes:		"MedlineHayward, Sean Tani, Akira Owen, Sue M Hewitt, C Nicholas eng Research Support, Non-U.S. Gov't Canada 2004/05/05 Tree Physiol. 2004 Jul; 24(7):721-8. doi: 10.1093/treephys/24.7.721"