We are interested in understanding how plants acquire information from the biotic and abiotic environment and integrate this information into responsive behavior. To address this question we have identified primary stress responsive genes by transcriptional profiling of plants 5 min post mechanical wounding, as an instantaneous and synchronous stimulus. Additional quantitative analyses of a wounding time-course classified the genes into two groups, transient and stably expressed. We have determined that the stress inducible alterations in transcriptional networks are mediated through a novelinducible cis-regulatory element, now designated as RSRE (Rapid Stress Response Element; RSRE). This motif is present in the promoters of an array of diverse stress-responsive genes. To begin to identify regulatory components in this signaling network, we have generated an RSRE::luciferase(LUC)-transgenic line. By using these plants in an imaging-based assay we determined that this element is sufficient to confer a rapid response to both biotic and abiotic stresses in vivo, thereby establishing the functional involvement of this motif in primary transcriptional stress responses.  We are now using an imaging-based genetic screen to identify mutants that express LUC constitutively.  Subsequent map-based cloning of genes responsible for the constitutive expression will enable us to dissect initial components of the stress network.

In addition we are also examining the coordinating regulatory role of a selected group of transiently stress-inducible genes in the initial stress response network.