Phylogenetic relationship between Pto(−like) ( sensu strictu and sensu latu ) and the RLK/Pelle subfamily CrRLK1L. The Neighbor-joining analysis was based on the aa sequences of: Pto and paralogs of Solanum pimpinellifolium and the other solanaceous Pto-like (i.e. Pto-like sensu strictu); representative CrRLK1L of Arabidopsis (◊), rice (◊) and Catharanthus roseus (◊); Pto best blastp matches (namely CrRLK1L, based on domain composition) of Arabidopsis, rice, grapevine, poplar and castor bean; Pto-like fragments of non-solanaceous species (Phaselus vulgaris, cultivated and wild strawberry and Musa acuminata) (namely CrRLK1L-like, i.e. Pto-like sensu latu); best blastp matches from F. vesca and P. vulgaris (namely CrRLK1L) obtained using Pto-like fragments from the same species, as query. Representative CrRLK1L-like of Pac obtained with Pto-primer were also included (pac, ♦). Black arrows indicate the only solanaceous so-called Pto-like sequences, which clustered within a CrRLK1L-headed clade. The black star indicates a CrRLK1L of castor bean lacking the extracellular domain typical of the subfamily. The kinase domain region spanned subdomain I up to the beginning of IX. See caption of Figure 1 for additional details on the representation of the tree.