Phylogenetic analysis of the three barley SERK proteins and other plant SERK amino acid sequences. OsSERK1 (BAD05545.1), OsSERK2 (XP_015636497.1) from Oryza sativa; TaSERK1 (AEP14551.1) and TaSERK2 (AEP14552.1) from Triticum aestivum; ZmSERK1 (NP_001105132.1), ZmSERK2 (CAC37639.1), and ZmSERK3 (CAC37642.1) from Zea mays; SbSERK1 (EES13434.1), SbSERK2 (XP_002447957.1), and SbSERK3 (XP_002454054.1) from Sorghum bicolor; SlSERK1 (NP_001233866.1) from Solanum lycopersicum; AtSERK1 (NP_177328.1), AtSERK2 (AAK68073.1), AtSERK3 (AAK68074.1), At-SERK4 (NP_178999.2), and AtSERK5 (NP_179000.3)from Arabidopsis thaliana. The red arrows show SERK proteins from Hordeum vulgare L.