Unrooted phylogenetic tree of GHF5 catalytic domains based on the protein sequences using the maximum likelihood method. The GHF5 proteins from A. avenae (AA-ENG-1 and AA-ENG-2) are labeled in bold. GenBank accession numbers of GHF5 proteins from Meloidogyne incognita (MI-ENG-1, MI-ENG-2, MI-ENG-3 and MI-ENG-4), Pratylenchus penetrans (PP-ENG-1 and PP-ENG-2), Pratylenchus coffeae (PC-ENG-1), Radopholus similis (RS-ENG-1A, RS-ENG-1B, RS-ENG-2 and RS-ENG-3), Globodera rostochiensis (GR-ENG-1, GR-ENG-2 and GR-ENG-4), Heterodera glycines (HG-ENG-2, HG-ENG-4, HG-ENG-5 and HG-ENG-6), Ditylenchus africanus (DA-ENG-1), beetles, bacteria and protists are indicated in brackets. The bootstrap values are calculated from 1000 replicates. The scale bar represents 10 substitutions per 100 amino acid positions.