Research activities Molecular Physiology

Department Prof. Dr. Dorothea Bartels

The research group is concerned with the molecular basis of drought tolerance in higher plants. Our studies are focused on the desiccation tolerant South African resurrection plant Craterostigma plantagineum that can adapt to extreme drought. The picture below shows the fully hydrated plant, the middle panel shows the desiccated plant and the right hand side shows the plant twenty four hours after re-watering.

This plant originates from South Africa and has the remarkable ability to survive desiccation. The plant can survive in this dry stage for a long time. Many genes have been isolated that are involved in survival of desiccation. Some of the genes are homologous to genes that are found in embryos of maturing seeds. This observation indicates that desiccation tolerance in vegetative tissues of resurrection plants involves similar mechanisms as desiccation tolerance in seeds of higher plants. The functional analysis of these genes and the corresponding proteins are important research subjects. Understanding regulation of gene expression is another important research focus in order to understand how a network of molecules is interacting to keep cellular components functional in the absence of water.

In order to identify essential components of desiccation tolerance we are studying close relatives of C. plantagineum which differ in desiccation tolerance. We are comparing transcript and protein expression patterns, carbohydrate accumulation, oxidative stress responses and lipid changes. This comparative approach should help to define the requirements for a desiccation tolerant phenotype.

In addition we have a project which deals with the functional analysis of the aldehyde dehydrogenase gene family in the genetic model species Arabidopsis thaliana. Aldehyde dehydrogenases (ALDHs) are a family of enzymes which catalyze the oxidation of reactive aldehydes to their corresponding carboxylic acids.  Aldehyde molecules are involved in many metabolic processes but when they accumulate in excess they become toxic. The activity of aldehyde dehydrogenases is important in regulating the homeostasis of aldehydes. Overexpression of some ALDHs demonstrated an improved abiotic stress tolerance in plants. Molecular genetic approaches are used to identify the metabolic pathways in which the different aldehyde dehydrogenase genes are involved in.

A third central research activity is the investigation of the barley root architecture under osmotic stress using in vitro systems.

Research Projects
In Progress ...