Comparative proteome analysis of metabolic proteins from seeds of durum wheat (cv. Svevo) subjected to heat stress.

Abstract

In Central and Southern Italy, where durum wheat represents one of the most widely cultivated crops, grain filling occurs during Spring, a period characterised by sudden increases in temperature. Wheat grain proteins are classified into albumins, globulins, and prolamins. The non-prolamin fractions include proteins with metabolic activity or structural function. In order to investigate the consequences of heat stress on the accumulation of non-prolamin proteins in mature durum wheat kernels, the Italian cultivar Svevo was subjected to two thermal regimes (heat stress vs. control) during grain filling. The 2D patterns of non-prolamin proteins were monitored to identify polypeptides affected by heat stress. This study shows that heat stress alters significantly the durum wheat seed proteome, although the fold changes range only between 1.2 and 2.2. This analysis revealed 132 differentially expressed polypeptides, 47 of which were identified by MALDI TOF and MALDI-TOF-TOF MS and included heat shock proteins, proteins involved in the glycolysis and carbohydrate metabolism, as well as stress related proteins. Many of the heat induced polypeptides are considered to be allergenic for sensitive individuals. The differences observed with previously reported data regarding bread wheat may be explained by the absence of the D genome in durum wheat