Journal Article

Print(0)

Tree physiology

Tree Physiol.

/

24

7

721

728

0829-318X

Unknown(0)

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 ∼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 μmol m-2 s-1 and a maximum between 35 and 38°C. Under standard conditions of 30°C and 1000 μmol m -2 s-1 PPF, the mean isoprene E was 13 μg g dm-1 h-1, considerably higher than previously observed in this species. Mean E for acetaldehyde, methanol and monoterpenes at 30°C were 0.37, 0.78 and 2.97 μg 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 ∼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.

1,3 butadiene derivative, acetaldehyde, hemiterpene, isoprene, methanol, pentane, terpene, article, light, mass spectrometry, metabolism, physiology, spruce, temperature, tree

MEDLINE

Embase

Hayward,S., Tani,A., Owen,S. M., Hewitt,C. N.

Hewitt, C.N., Inst. of Environ. and Nat. Sciences, Lancaster University, Lancaster, LA1 4YQ, United Kingdom

http://vp9py7xf3h.search.serialssolutions.com/?charset=utf-8&pmid=

2004