KNOX genes play crucial roles in cell-fate determination and body plan specification during early embryogenesis. However, the specific gene structure and functional differentiation of KNOXs in Brassica napus is still unclear. We investigated KNOX genes in Brassica rapa (B. rapa), Brassica oleracea (B. oleracea), and Brassica napus (B. napus), which are polyploidy models with genome triplication after Arabidopsis-Brassiceae divergence. In total, 15, 14, and 32 KNOX genes were identified in B. rapa, B. oleracea, and B. napus, respectively. Phylogenetic analysis classified BnKNOXs (B. napus) into...