Morker, K H , Roberts, M R .
Early signals in the wound response of Arabidopsis thaliana.
Various signalling pathways are involved in the response to wounding in plants. However, the mechanisms by which plants initially perceive wounding are largely unknown. We have investigated two early responses to wounding that may represent primary mechanisms for sensing leaf damage. The first of these is the generation of reactive oxygen species (ROS), which have previously been suggested as signals in the wound response. Using histochemical assays and luminescence imaging, we have established that superoxide, hydrogen peroxide and singlet oxygen are all generated in leaves within minutes of wounding. Furthermore, we have identified the primary site of superoxide and hydrogen peroxide generation as the chloroplast, as a direct result of perturbation of photosynthetic electron transport. The major burst of ROS produced in response to wounding is, therefore, light-dependent. In order to investigate more fully the interaction between light and wound stress, we have used microarray analysis to explore wound-induced changes in the Arabidopsis transcriptome in the light and in the dark. Whilst both wounding and light/dark shifts have a major impact on the transcriptome, we have identified only a few significant interactions between the two conditions. Secondly, we have identified both molecular and physiological responses to changes in leaf water relations that occur rapidly in wounded leaves. Current experiments are focussed on determining the signals involved in mediating changes in stomatal conductance, transpiration and assimilation by gas exchange measurements in wild type and mutant plants.
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1 - Lancaster University, Biological Sciences, Bailrigg, Lancaster, Lancashire, LA1 4YW, UK
2 - Lancaster University, Biological Sciences
reactive oxygen species
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM