RECEPTOR-LIKE PROTEIN REQUIRED FOR CSP22 RESPONSIVENESS (NbCSPR) underlies age-dependent immune responses to bacterial cold shock protein in Nicotiana benthamiana.
I. SAUR (1), Y. Kadota (2), N. Holton (3), J. Sklenar (3), E. Smakowska (4), Y. Belkhadir (4), C. Zipfel (3), J. Rathjen (5) (1) Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Germany; (2) Plant Immunity Research Group, RIKEN Center for Sustainable Resource Science, Japan; (3) The Sainsbury Laboratory, United Kingdom; (4) Gregor Mendel Institute of Molecular Plant Biology GmbH, Austrian Academy of Sciences, Austria; (5) Research School of Biology, The Australian National University, Australia

Plants employ receptor kinases (RKs) and receptor-like proteins (RLPs) to sense pathogen-associated molecular patterns (PAMPs). After ligand perception, many leucine-rich repeat (LRR)-containing receptors interact with the LRR-RK BRI1-ASSOCIATED KINASE 1 (BAK1). Here, we used BAK1 as molecular bait to identify an LRR-RLP required for the recognition of the csp22 peptide derived from bacterial PAMP ‘cold shock protein’. We established a biochemical method to identify proteins that interact with BAK1 after csp22 treatment. BAK1 was expressed transiently in Nicotiana benthamiana, and immunopurified after treatment with csp22. BAK1-associated proteins were identified by mass spectrometry. We identified several proteins including known BAK1 interactors, and an undescribed LRR-RLP that we termed NbCSPR. This novel RLP associates with BAK1 upon csp22 treatment, and NbCSPR-silenced plants are impaired in csp22-induced defense responses. NbCSPR confers resistance to bacteria in an age-dependent and flagellin-induced manner. NbCSPR limits bacterial growth and Agrobacterium-mediated transformation of flowering N. benthamiana plants. Knocking-out or silencing the expression of the NbCSPR may thus improve Agrobacterium-mediated transformation of N. benthamiana. Transgenic expression of NbCSPR in Arabidopsis thaliana conferred responsiveness to csp22 and anti-bacterial resistance. Our method may be used to identify other RKs or RLPs required for PAMP perception/responsiveness.

Abstract Number: C9-3, P17-653
Session Type: Concurrent