A LysM-receptor kinase mediates chitin elicitor signaling in rice

Abstract

We recently showed that CERK1 (Chitin Elicitor Receptor Kinase 1), a receptor-like kinase with extracellular LysM domains, is an essential component for chitin elicitor signaling in A. thaliana1). In rice genome, ten receptor-like kinase genes with LysM domains, named as OsLysM-RLKs, were found. Among these, OsLysM-RLK9 showed the highest homology with CERK1 and thus analyzed for its function in chitin elicitor signaling in rice. Knock-down transformants of OsLysM-RLK9 were established to analyze the function of this molecule. Several lines of these transformants showed significantly reduced expression of OsLysM-RLK9 but not of CEBiP (Chitin Elicitor Binding Protein) 2). These lines showed almost no ROS generation as well as phytoalexin biosynthesis in response to chitin oligosaccharide elicitor. These results indicated that OsLysM-RLK9 plays an essential role for chitin elicitor signaling in rice, somehow collaborating with CEBiP.
1)Miya et al., PNAS, in press; 2)Kaku et al., PNAS, 103, 11086 ('06)