Fig. 6

Phylogenetic analysis of Brassicaceae BKN and closely-related RLCK group VIIa protein sequences. Sequences are from Arabidopsis thaliana, A. lyrata, A. halleri, Arabis alpina, Boechera stricta, Brassica cretica, B. oleracea, Capsella rubella, C. grandiflora, Eutrema salsugineum (formerly T. halophila), Schrenkiella parvula (formerly T. parvula), Aethionema arabicum, Tarenaya hassleriana, and Carica papaya. Red branches represent the BKN clade, Magenta branches represent the At5g25440-related RLCKs, Blue branches represent the At1g76360-related RLCKs, Green branches represent the CST (At4g35600)-related RLCKs. A. thaliana protein sequences for At5g25440.1, At1g76360.1 and At4g35600.2 were selected for searches and phylogenetic analyses as they clustered with the BKNs in the RLCK-VIIa tree (Additional file 1: Figure S7). KIN10 (At3g01090.2, SnRK1 kinase) was chosen as an outgroup. The analysis involved 90 amino acid sequences and the sequences were aligned using ClustalW [62] in the MEGA 7 software [63]. The N-and C-terminal ends of the alignment were trimmed (see Supplemental files for sequences and alignment), and the tree was constructed using the Maximum Likelihood method [64] in the MEGA 7 software. All positions containing gaps and missing data were eliminated, and a total of 28 positions was in the final dataset. The tree generated in MEGA 7 represents the bootstrap consensus tree inferred from 1000 replicates [65]