Detection of physically interacting proteins with the CC and NB-ARC domains of a putative yellow rust resistance protein, Yr10, in wheat

Abstract

Gene-for-gene (GFG) resistance is a potent defense mechanism in plants, that is mediated by resistance (R) proteins. In GFG resistance, pathogen effector or avirulence (Avr) proteins are recognised by R-proteins which initiate a series of signal transduction events that lead to hypersensitive cell death. In cereals, many R-proteins are comprised of an N-terminal coiled-coiled (CC) domain, a Nucleotide Binding (NB) domain and a Leucine Rich Repeats (LRR) region associated with effector recognition. NB-LRR immunity proteins are highly conserved across plant and animal taxa. To advance understating of signal transduction events in cereals, we exploited the high level of protein conservation to first identify yeast gene products interacting with the CC and NB domains of the candidate yellow rust R-protein (Yr10). Screening revealed proteins having mostly apoptosis related functions (Signal Recognition Particle 72kDa (SRP72); Chromosome SEgregation 1 (CSE1); ARrest Defective 1 (ARD1), translation initiation control in response to stress conditions (General Control Nonderepressible 2 (GCN2)), and a HSP90 co-chaperone (Cyclosporin-sensitive proline rotamase 7 (CPR7)). We then identified the close homologues of the interactors in barley and show that they were induced at 6h and/or 12 h after infection in Mla3 mediated Powdery Mildew (Blumeria graminis f.sp. hordei, Bgh) disease resistance, suggesting their involvement in pathogen response.