Table 4. Phylogenetic tree of WRKY TFs of dicot and lower eukaryotic plants.

Group IIa (red)	Group IIb (lime)	Group IIc (blue)	Group I (pink)	Group III (green)
1, 2, 3, 4, 5, 6, 9, 10, 12, 18, 19, 20, 21, 25, 26, 31, 32, 33, 34, 36, 40, 42, 44, 47, 58, 60, 61, 72	3, 4, 5, 8, 10, 13, 23, 24, 28, 43, 45, 48, 49, 50, 51, 56, 57, 59, 68, 71, 75	3, 4, 33, 45, 51	7, 11, 14, 15, 16, 17, 19, 20, 21, 22, 27, 29, 35, 39, 52, 64, 65, 69, 74	30, 38, 41, 46, 53, 54, 55, 62, 64, 66, 67, 70

The phylogenetic tree revealed three phylogenetically distinct groups. The WRKY TF members of groups I, II and III are distributed redundantly. The WRKY members of one group were present in the other groups. This grouping was similar to that reported in previously studies such as groups IIa, IIb, and IIc. The members of groups I and III are significantly specific to their own groups, no members of one group overlap with another. These findings confirm that the nomenclatures of all WRKY TFs are correct. This nomenclature and grouping system should be applied to dicot plants only. Groups I, II, III, IV, V and VI of monocot plants is not the same as that of the respective group of dicots. Hence it is highly recommended to follow lineage specific grouping system to avoid any confusion. The numbers indicate the WRKY TF members distributed in different groups (1, 2, etc. indicate WRKY1, WRKY2 etc.). The phylogenetic tree was constructed using MEG6 software and Poisson substitution model by using 1000 bootstrap replicates.