From defense to symbiosis: limited alterations in the kinase domain of LysM receptor‐like kinases are crucial for evolution of legume–Rhizobium symbiosis

• DOI: 10.1111/j.1365-313x.2010.04411.x
• Publication Date: 2010-10-20T04:33:21Z
• Authors: Tomomi Nakagawa; Hanae Kaku; Yoshikazu Shimoda; Akifumi Sugiyama; Masayuki Shimamura; Kojiro Takanashi; Kazufumi Yazaki; Toshio Aoki; Naoto Shibuya; Hiroshi Kouchi
• Keywords: Lotus japonicus; Nod factor; Protein kinase domain

Summary Nitrogen‐fixing symbiosis between legumes and rhizobia is initiated by the recognition of rhizobial Nod factors (NFs) host plants. NFs are diversely modified derivatives chitin oligosaccharide, a fungal elicitor that induces defense responses in Recent evidence has shown both elicitors recognized structurally related LysM receptor kinases. Transcriptome analyses Lotus japonicus roots indicated not only activate genes but also transiently defense‐related through NF receptors. Conversely, oligosaccharides were able to independently Analyses using chimeric consisting domain receptor, NFR1, kinase an Arabidopsis CERK1, demonstrated substitution portion αEF helix CERK1 with amino acid sequence YAQ from corresponding region NFR1 enables L. nfr1 mutants establish Mesorhizobium loti . We showed domains two kinases, Lys6 Lys7, which possess sequence, suppress symbiotic defect These results strongly suggest that, addition adaptation extracellular NFs, limited alterations receptors have played crucial role shifting intracellular signaling responses, thus constituting one key genetic events evolution root nodule legume