Powdery mildew fungi acquire nutrients from plant cells through haustoria, which they place in living host epidermal cells. This is based on formation of an extrahaustorial membrane (EHM) by the plant cell. We can predict that a number of vesicle trafficking proteins must be involved in this process, and we want to suppress these to search for the membrane traffic pathway leading to EHM formation.

Transformed cells with expression of a GUS reporter gene. Haustorium formed successfully (A). No haustorium formed (B)

In the project, we will use the barley-powdery mildew system. Here we will make transient induced gene silencing (TIGS) by the help of RNAi, and transient over-expression of dominant-negative membrane proteins. Transient expression of gene constructs will be obtained by particle bombardment of barley leaves with DNA-coated gold particles. Afterwards the leaves are inoculated with the powdery mildew fungus, and later the growth and haustorial formation of the fungus will assayed by microscopy.

The results will be important in future design of disease resistent plants.

Key-words: molecular biology, genetics, pathogen, vesicle trafficking, barley


Particle bombardment chamber
The project will include the following:

1. Making of RNAi and dominant-negative constructs
2. Transient expression in barley epidermal cells
3. Microscopy for evaluating haustoria formation
4. Unravelling of EHM formation and what membrane it is

Contact

Henrik Böhlenius & Hans Thordal-Christensen (photo)

Section for Plant and Soil Science

Department of Plant and Environmental Sciences

Thorvaldsenvej 40

1871 Frederiksberg C.
Tlf.: 3533 3443, E-mail: