Prof. Beat Keller - Molecular Plant Biology Phytopathology

In our group, we are interested in the molecular function of disease resistance genes in wheat. In an integrated approach we study both the immune receptors on the plant side as well as the recognized effectors in the pathogen. A focus is on the powdery mildew disease caused by the fungal pathogen Blumeria graminis f.sp. tritici (Bgt). There, we study the Pm3 allelic series encoding NLR immune receptors, the Pm8 and Pm17 orthologs in rye and the mildew effectors recognized by these genes. This work relies on pathogen genomics and in addition to the molecular isolation and functional analysis, we study avirulence effector evolution and diversity. Among others, our projects in evolutionary biology have revealed that mildew adaptation on the novel host crop Triticale is caused by hybridization. Finally, in a translational approach, modified immune receptors have been transformed into wheat and the resulting genotypes are tested in the field (www.protectedsite.ch).

In addition to effector triggered, NLR-based immunity, we also study quantitative and durable leaf rust resistance in the Swiss winter wheat variety “Forno”, and we have molecularly identified the Lr14a and Lr34 genes as two major QTL controlling resistance. Functional studies of these two genes are ongoing. We have recently identified genes encoding a tandem kinase (WTK4) and a kinase-MCTP (Pm4) as novel, race-specific powdery mildew resistance genes. Several projects in the group aim at the characterization of molecular function of these genes in wheat immunity as well as at the identification of the recognized avirulence factors.

Based on the recent advances in wheat genomics and the availability of reference genome sequences we are aiming at the molecular identification of novel resistance genes in genetic material stored in genebanks or available as breeding lines.

Our work is based on the knowledge and genetic characterization of disease resistance in wheat by breeders and geneticists during hundred years of wheat breeding, and we are inspired by the enormous natural genetic diversity in this crop. We want to contribute to the molecular characterization of this diversity, and we also aim at translational work to support wheat breeding for disease resistance.