Identification and sequence analysis of putative Sulla species nod factor receptor

In legumes, LysM domains of receptors-like kinases (RLKs) mediate rhizobial NFs perception; which are required for infection and establishment of symbiosis without triggering the host immune response. In this study, we identify the LysM extracellular domain sequences of putative Sulla species Nod factor receptors (S. pallida, S. capitata and S. coronaria). The Blast search displayed high identity percentages with genes encoding LjNFR5-like of several legumes. Phylogenetic trees were built using the partial nod factor receptor and predicted amino acid sequences, which grouped Sulla in a separate clade. The multiple alignments of the LysM2 domains revealed that amino acids found to be important in other legume species are not conserved in Sulla species. Further examination of the predicted proteins sequences (LysM2 domain) showed that the three species were different in the two crucial sites for Nod factor perception.