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RNAi-mediated suppression of isoprene biosynthesis in hybrid poplar impacts ozone tolerance.
- Source :
-
Tree physiology [Tree Physiol] 2009 May; Vol. 29 (5), pp. 725-36. Date of Electronic Publication: 2009 Feb 13. - Publication Year :
- 2009
-
Abstract
- 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.
- Subjects :
- Antioxidants metabolism
Butadienes
Carbon Dioxide metabolism
Hemiterpenes genetics
Models, Biological
Pentanes
Plant Leaves drug effects
Plant Leaves genetics
Plant Leaves metabolism
Plant Stomata metabolism
Plant Transpiration drug effects
Plants, Genetically Modified drug effects
Plants, Genetically Modified metabolism
Populus drug effects
Populus metabolism
Hemiterpenes biosynthesis
Hybridization, Genetic
Oxidative Stress
Ozone pharmacology
Populus genetics
RNA Interference
Subjects
Details
- Language :
- English
- ISSN :
- 0829-318X
- Volume :
- 29
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- Tree physiology
- Publication Type :
- Academic Journal
- Accession number :
- 19324699
- Full Text :
- https://doi.org/10.1093/treephys/tpp009