Identification of two novel receptor kinases from tomato that act as the receptor sites for bacterial cold shock protein and the wound factor systemin 
L. WANG (1), M. Albert (1), G. Felix (1) (1) Center for Plant Molecular Biology, University of Tuebingen, Germany

Csp22 has been known as a MAMP since more than a decade but the corresponding PRR has not been identified yet. Similarly, systemin was discovered as the first plant peptide hormone 25 years ago but the receptor SR160 proposed for this DAMP-type ligand was strongly disputed and the genuine receptor remained unknown. We started with the observation that Solanum. pennellii, in contrast to the cultivated tomato Solanum. lycopersicum, lacks responsiveness to csp22 and systemin, indicating natural variation in perception of both peptides. By using well-defined recombinant inbred lines between the two species, responsiveness to both csp22 and systemin could be mapped to a common region in the tomato genome that comprises around two dozens of genes predicted to encode receptor like kinases or receptor like proteins. Expression of these individual receptor-type candidate genes in leaves of young N. benthamiana plants identified one receptor like kinase that strongly enhanced responsiveness to csp22 and another receptor like kinase that conferred sensitivity to systemin. Both receptors showed high affinity and specificity for their respective ligands in receptor binding assays and they proved functional also when heterologously expressed in Arabidopis cells. Furthermore, the CSP receptor could confer Arabidopsis increased resistance to the bacterial pathogen Pst DC3000, yet how perception of systemin by its receptor could benefit plants remains to be our future work.

Abstract Number: P17-636
Session Type: Poster