Molecular analysis of Arabidopsis thaliana LRR receptor protein kinases (LRR-RLK) implicated in pathogen defense

• Applicant: Professor Dr. Thorsten Nürnberger
• Subject Area: Ecology and Biodiversity of Plants and Ecosystems
• Term: from 2001 to 2007
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5352804

Leucine-rich repeat (LRR) proteins (LRRP) and LRR receptor-like kinases (LRR-RLK) have been implicated in the acivation of plant disease resistance. These proteins are believed to form large signal perception complexes with so far unknown interacting proteins. Since genes encoding components of signaling pathways in eukaryotes are often found to be transcriptionally up-regulated by the corresponding stimulus, we will exploit this to identify new LRR-RLK and LRRP-encoding genes potentially involved in disease restistance. To analyze and isolate signal perception complexes mediating the activation of plant defense responses we propose the following strategy: Arabidopsis thaliana Col-O plants will be infected with avirulent bacterial, oomycete, and fungal pathogens and will be also infiltrated with elecitors of plant defense reactions. RNA from infected plants will be used in RT-PCR assays with gene-specific primers (derived from the genomic database) or in cDNA microarray assays on LRRP/LRR-RLK-chips. Selected genes will be characterized with respect to their function in plant defense signaling (gene inactivation by T-DNA insertion or RNA interference and subsequent analysis of the mutants in infection assays). Biochemical characterization will involve isolation of interacting proteins with tagged LRRP/LRR-RLK bait-protein and identification of interacting proteins by tryptic fragmentation/MALDI-TOF spectroscopy.

• DFG Programme: Research Grants