INTEGRATED APPROACH TO UNDERSTAND THE FUNCTIONNING OF WHEAT QUALITY COMPONENTS AND THEIR INTERACTION WITH ENVIRONMENTS

The aggregative properties of wheat grain prolamins are largely responsible for the technological functionalities of the flours and semolina that will be extracted from bread-wheat and durum wheat, respectively. Indeed, the ability of wheat prolamins to form a plastic three-dimensional network during the mixing depends to a large extent on their ability to interact. These aggregative properties, which can be evaluated today by measuring their molecular weight distribution, is dependent on the polymorphism of the protein subunits present but also, to the environmental conditions that are applied during the grain development. Indeed, any modification of the redox status of the grain tissues in response to an oxidative stress can lead to a decrease in the degree of association of the prolamins by limiting the protein-protein interactions during the grain desiccation. Considering the current and future environmental imperatives (i.e. climate changes with increasing heat stress), it is essential to better understand these phenomena to implement new breeding strategies for a sustainable quality. For this purpose, an integrated approach allowing to investigate wheat components variation with Environments (E), Genotypes (G) and EXG is adopted. Researches on durum wheat (Triticum durum L.) with Tunisian (local and high yielding) varieties and on bread wheat (Triticum aestivum L.) with diverse French varieties, were carried out, through the collaboration between National Agronomic Institute of Tunisia-INAT and Polytechnic Institute Uni-Lasalle-Beauvais. Where, our main directions and activities are to investigate genotypes and evaluate the stability of their quality in different environments. Molecular identification, quantification and distribution were assessed for prolamins and starch components using EC-Lab-on-CHIP, HPLC, Asymetric Field Flow Fractionation, Spectroscopy. Our researches showed that it is very important to consider, in the improvement of wheat quality, the best behavior genotypes and their performance under poor environments; and explore potentialities by investigating relationships between agronomical, biochemical and technological parameters. On the basis of these relationships further investigations on end-products could contribute to the effectiveness of this integrated approach