Maximum-Likelihood (ML) tree of the gamma-gliadins (based on amino acid sequences). A maximum-likelihood (ML) analysis was performed with PhyML 3.0. SH-like approximate likelihood-ratio test was used for estimation of branch support. Proteins with a length in the alignment less than 200 amino acids were excluded from the analysis. The gamma-gliadins fall into six groups (1–6 on the right) in two branches (1–2 and 3-4-5-6). Key for the sequence codes in Additional file 1.