Isolation of the wheat aleurone layer for 2D electrophoresis and proteomics analysis

Whereas the endosperm of bread wheat has been studied for many years for obvious ecoomic reasons, studies of the aleurone layer of the seed only started recently after the discovery of its nutritional and health benefits. In this paper, we describe two different techniques to isolate either the peripheral layers including the aleurone layer or only the aleurone layer (AL) which can be used for 2D electrophoresis and proteomic analysis. The two techniques provided similar 2D electrophoresis profiles although the time needed for dissection of the kernel and isolation of the cell layer was different. The two 2D protein profiles shared more than 80% identity and enabled us to observe approximately 700 spots in the aleurone layer. Two bread wheat cultivars, Chinese Spring and Recital, were used and the two techniques revealed that their AL shared at least 70% of common spots. Several spots not present in AL and coming from peripheral layers were identified using mass spectrometry and database interrogation. These dissection techniques will enable proteomic analysis of AL which can be used for genetic analysis of its components, for investigating the AL response to fungi attack and helpful for improving nutritional and health value of wheat.