Phenotypic Analyses of the gpa3 Mutant.
(A) Grain-filling process in the wild type and the gpa3 mutant. Values are means ± sd (n = 3).
(B) Transverse sections of representative wild-type and gpa3 mutant dry seeds. Bars = 1 mm.
(C) Scanning electron microscopy images of transverse sections of wild-type and gpa3 mutant grains. Bars = 10 μm.
(D) SDS-PAGE storage protein profiles of dry seeds from the wild type and the gpa3 mutant. pGT, proglutelins; αGT, glutelin acidic subunits; αGlb, α-globulin; βGT, glutelin basic subunits; Pro, prolamins.
(E) Immunoblot analysis of storage proteins from dry seeds of the wild type and the gpa3 mutant, using antiglutelin and anti-α-globulin specific antibodies. Possible partial degradation products of glutelins and α-globulins are labeled with asterisks.
(F) Immunoblot analysis of the glutelin subfamily proteins (GluA, GluB, and GluC) and the molecular chaperones BiP1 and PDI1-1.
Arrows denote the 57-kD proglutelins, while arrowheads indicate the glutelin acidic subunits (black) and basic subunits (red). Antitubulin antibodies were used as a loading control in (E) and (F).