The phylogenetic relationships and gene structure of cucumber auxin response-related genes. The left part in different panel illustrates the relationships among the cucumber ARF (a), AUX/IAA (b) GH3 (c), LBD (d) proteins. The unrooted phylogenetic tree was generated using MEGA4.1 through the neighbor joining method. Bootstrap values (above 50%) from 1,000 replicates are indicated at each branch. The right part illustrates the exon–intron organization of ARF (a), AUX/IAA (b) GH3 (c) , LBD (d) family genes. The exons and introns are represented by black boxes and lines, respectively.