TY  - JOUR
AU  - Behnke, K.
AU  - Kleist, E.
AU  - Uerlings, R.
AU  - Wildt, J.
AU  - Rennenberg, H.
AU  - Schnitzler, J.-P.
TI  - RNAi-mediated suppression of isoprene biosynthesis in hybrid poplar impacts ozone tolerance
JO  - Tree physiology
VL  - 29
SN  - 0829-318X
CY  - Victoria, BC
PB  - Heron
M1  - PreJuSER-3492
SP  - 725 - 736
PY  - 2009
N1  - The authors thank Ursula Scheerer for ascorbate and glutathione analyses and Sandrine Louis for helpful comments on the manuscript. This work was supported by the German Science Foundation (DFG) (SCHN653/4 to J.-P.S., RE515/20 to H.R.) within the German joint research group 'Poplar - A Model to Address Tree-Specific Questions'.
AB  - Isoprene is the most abundant volatile compound emitted by vegetation. It influences air chemistry and is thought to take part in plant defense reactions against abiotic stress such as high temperature or ozone. However, whether or not isoprene emission impacts ozone tolerance of plants is still in discussion. In this study, we exploited the transgenic non-isoprene emitting grey poplar (Populus x canescens (Aiton) Sm.) in a biochemical and physiological model study to investigate the effect of acute ozone stress on the elicitation of defense-related emissions of plant volatiles, on photosynthesis and on the antioxidative system. We recorded that non-isoprene emitting poplars were more resistant to ozone as indicated by less damaged leaf area and higher assimilation rates compared to ozone-exposed wild-type (WT) plants. The integral of green leaf volatile emissions was different between the two poplar phenotypes and was a reliable early marker for subsequent leaf damage. For other stress-induced volatiles, such as mono-, homo- and sesquiterpenes and methyl salicylate, similar time profiles, pattern and emission intensities were observed in both transgenic and WT plants. However, unstressed non-isoprene emitting poplars are characterized by elevated levels of ascorbate and alpha-tocopherol as well as by a more effective de-epoxidation ratio of xanthophylls than the WT. Since ozone quenching properties of ascorbate are much higher than those of isoprene and furthermore alpha-tocopherol is also an essential antioxidant, non-isoprene emitting poplars might benefit from changes within the antioxidative system by providing them with enhanced ozone tolerance.
KW  - Antioxidants: metabolism
KW  - Butadienes
KW  - Carbon Dioxide: metabolism
KW  - Hemiterpenes: biosynthesis
KW  - Hemiterpenes: genetics
KW  - Hybridization, Genetic
KW  - Models, Biological
KW  - Oxidative Stress
KW  - Ozone: pharmacology
KW  - Pentanes
KW  - Plant Leaves: drug effects
KW  - Plant Leaves: genetics
KW  - Plant Leaves: metabolism
KW  - Plant Stomata: metabolism
KW  - Plant Transpiration: drug effects
KW  - Plants, Genetically Modified: drug effects
KW  - Plants, Genetically Modified: metabolism
KW  - Populus: drug effects
KW  - Populus: genetics
KW  - Populus: metabolism
KW  - RNA Interference
KW  - Antioxidants (NLM Chemicals)
KW  - Butadienes (NLM Chemicals)
KW  - Hemiterpenes (NLM Chemicals)
KW  - Pentanes (NLM Chemicals)
KW  - Ozone (NLM Chemicals)
KW  - Carbon Dioxide (NLM Chemicals)
KW  - isoprene (NLM Chemicals)
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
C6  - pmid:19324699
UR  - <Go to ISI:>//WOS:000265850500010
DO  - DOI:10.1093/treephys/tpp009
UR  - https://juser.fz-juelich.de/record/3492
ER  -