BACKGROUND: Powdery mildew (Blumeria graminis f.sp.Tritici,Bgt) is the most devastating foliar fungal disease.To investigate influences of powdery mildew on wheat grain at varying levels of disease severity and at different growth stages,exploration occurred under field conditions and at an aggregated level.Methods used to determine these effects included Kjeldahl determination,unidimentional polyacrylamide gel electrophoresis,dielectrophoresis combined with mass spectrometric analysis,and other methods.RESULTS: The specific influences explored were those on prolamins and protein composition at the molecular level.Concentrations of both grain protein content (GPC) and prolamin protein in wheat grains showed an increasing trend with the aggravation of powdery mildew.This was caused by a severe increase in expression levels of metabolic enzymes and molecular chaperone,such as peptidyl-prolyl isomerase (PPIase),cyclophilin A-2,and GTP enzyme ObgE,in wheat grain under powdery mildew stress.CONCLUSION: Powdery mildew stress could somehow promote GPC synthesis,and particularly prolamin synthesis,resulting in a change of the relative contents of all protein components.