Integrated Proteome Analysis of the Wheat Embryo and Endosperm Reveals Central Metabolic Changes Involved in the Water Deficit Response during Grain Development

The embryo and endosperm of wheat
have different physiological
functions and large differences in protein level. In this study, we
performed the first integrated proteome analysis of wheat embryo and
endosperm in response to the water deficit during grain development.
In total, 155 and 130 differentially expressed protein (DEP) spots
in the embryo and endosperm, respectively, were identified by nonlinear
two-dimensional electrophoresis and tandem mass spectrometry. These
DEPs in the embryo were mainly involved in stress/defense responses
such as heat shock-related proteins (HSP) and peroxidase, whereas
those in endosperm were mainly related to starch and storage protein
synthesis such as α-amylase inhibitor and the globulin-1 S allele.
In particular, some storage proteins such as avenin-like proteins
and high-molecular weight glutenin subunit Dy12 displayed higher expression
levels in the mature endosperm under a water deficit, which might
contribute to the improvement in the quality of breadmaking.