Differential Protein Accumulation during Barley Grain Development

Barley grains were analysed during development for the presenceof salt-soluble proteins, hordeins and glutelins. Characteristictemporal differences between the fractions were observed withhordeins being produced relatively late during maturation. Analysisof this fraction by gel electrophoresis revealed differentialaccumulation of its component polypeptides. The C hordeins madeup a relatively higher percentage of total hordein at the earlystages, decreasing from 20% of the total at 33% final dry weightto 15% at maturity. The relative amount of the lowest molecularweight B hordein band (Bl) increased throughout developmentfrom 30% of the total at 33% final dry weight to about 45% atmaturity. Electrophoresis of the salt-soluble fraction showedthat a group of low molecular weight polypeptides appeared atthe same stage of development as did the hordeins. There wereonly relatively minor changes in the polypeptide compositionof the glutelin fraction.