Functional analysis of Arabidopsis leucine-rich repeat receptor-like kinases (LRR-RLK) with dual roles in plant immunity and development

• Applicant: Professor Dr. Thorsten Nürnberger
• Subject Area: Plant Cell and Developmental Biology
• Term: from 2007 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 49886109

Receptor-like kinases (RLK) serve various roles in plants. The vast number of Arabidopsis leucine-rich repeat RLK (LRR-RLK) genes and the fact that a few of the encoded proteins are implicated in plant immunity suggest that various LRR-RLKs play predominant roles in plant-pathogen interactions. As contributors to the AtGenExpress Initiative we have conducted gene expression profiling experiments on microbe-infected plants. Our studies revealed 49 (out of 228) LRR-RLK genes whose expression was increased upon infection. Some of the encoded proteins were shown to contribute to plant immunity. BAK1 (BRI1-Associated Kinase1) regulates the containment of microbial infection-induced necrosis and resistance against necrotrophic fungi. Importantly, impaired immunity in bak1 mutants is independent of the phytohormone, brassinolide (BL). Thus, BAK1 appears to serve BL-dependent and independent functions in development and immunity. Likewise, PSKR1 (pentasulfokine receptor 1) represents another LRR-RLK with dual roles in plant immunity and development. Dual function proteins are considered nodes in partially overlapping biological programs whose regulation is often unknown. We will therefore address what determines specificity of the two proteins in development and immunity. The proposed work aims at identification and characterization of proteins interacting with BAK1 or PSKR1, respectively. Our research will intensify established links to US and German Partners who study development-associated LRR-RLKs.

• DFG Programme: Research Grants
• Participating Person: Privatdozentin Dr. Birgit Kemmerling