Abstract

My group is interested in the pathways leading from stress perception, through signal transduction, to stress gene expression and altered tolerance, as well as in the fundamental basis of stress tolerance itself. Our most recent work has focussed upon three areas (1) the role of calcium in mediating appropriate patterns of stress gene expression; (2) the mechanisms of drought tolerance in Sorghum bicolor; (3) investigating genetic components of freezing tolerance in Arabidopsis and Arctic plant species. In the first project, we have taken a transcriptomic approach not only to define the specific transcription factor systems that are regulated by calcium, but also to begin to understand how calcium encodes information that specifies the correct pattern of gene expression. We are now focussing attention of the photosynthetic organelle, the chloroplast, and I will present new work on this. In the second project, we have focussed upon Sorghum bicolor with the aim of uncovering potentially novel drought-tolerance pathways/mechanisms. This species is highly drought-adapted compared to other crops, and extremely drought tolerant “stay-green” Sorghum lines have been isolated, and the genetic loci responsible have been mapped by our collaborators. We have undertaken a transcriptomic approach to describe the fundamental processes underlying the stay-green phenomenon to help us understand why these lines are particularly drought tolerant and allow us to exploit this information. Finally, in the last project, we have used classical forward genetic screens to identify news genes/pathways involved in freezing stress tolerance in Arabidopsis, which I will discuss in my presentation. Related to this our work on Arctic species, only recently initiated, involves studying plants whose freezing tolerance is profound i.e. plants from the Arctic where a temperature of -40oC is not unusual in winter. By cloning and functionally testing alleles of genes known to be key genetic determinants in freezing tolerance, we hope to start to understand how the proteins involved have evolved to enhance freezing tolerance in these species. Understanding how such proteins from Arctic plants are able to mediate much greater levels of freezing tolerance will allow us to breed more freezing-tolerant crops.