Fig 2. Exon-intron structure of 57 MeHDZ genes in cassava.

The phylogenetic tree was constructed by Maximum-Likelihood method with 1000 bootstrap replicates. The MeHDZ genes were clustered into four groups, I to IV. Exon-intron analysis was performed using GSDS (http://gsds.cbi.pku.edu.cn/). Length of exons and introns of each MeHDZ gene was displayed proportionally. Upstream was defined as the sequences before the transcription start site ‘ATG’, while downstream was defined as the sequences after the stop codon (e.g., ‘TAA’).