Down-Regulating γ-Gliadins in Bread Wheat Leads to Non-Specific Increases in Other Gluten Proteins and Has No Major Effect on Dough Gluten Strength

BACKGROUND: Gliadins are a major component of gluten proteins but their role in the mixing of dough is not well understood because their contribution to wheat flour functional properties are not as clear as for the glutenin fraction. METHODOLOGY/PRINCIPAL FINDINGS: Transgenic lines of bread wheat with γ-gliadins suppressed by RNAi are reported. The effects on the gluten protein composition and on technological properties of flour were analyzed by RP-HPLC, by sodium dodecyl sulfate sedimentation (SDSS) test and by Mixograph analysis. The silencing of γ-gliadins by RNAi in wheat lines results in an increase in content of all other gluten proteins. Despite the gluten proteins compensation, in silico analysis of amino acid content showed no difference in the γ-gliadins silenced lines. The SDSS test and Mixograph parameters were slightly affected by the suppression of γ-gliadins. CONCLUSIONS/SIGNIFICANCE: Therefore, it is concluded that γ-gliadins do not have an essential functional contribution to the bread-making quality of wheat dough, and their role can be replaced by other gluten proteins.