Axis 2 - Control the protein composition to adapt it to the uses

In a first part, we analyze the mechanisms regulating the synthesis of the different storage proteins. The organization and variability of the genes (including promoter regions for some of them) encoding the storage proteins is examined in collaboration with other teams of the unit (FSOV ExIGE and ISite deliverable 4 projects). The effects of nitrogen and sulphur nutrition and temperature on the transcriptional regulation of high molecular weight glutenin synthesis are analyzed (ISite deliverable 4, Wheatomix). The transcriptional regulation of storage protein synthesis includes a network of DNA-protein and protein-protein interactions. Analyses of interactions between specific cis-motifs and transcription factors from the literature, the genetic approach of association and interaction networks are performed in vitro and in vivo (e.g. delay gel). To go beyond the current model, other work is envisaged such as the identification of proteins acting in complex with known regulatory proteins and the study of ABA regulation on the synthesis of storage proteins. Finally, a small number of candidate genes or proteins for the synthesis of storage proteins in response to nutrition have been identified by cross-approaches (networks, association genetics) and some of them will be functionally validated.

In a second part, we are seeking to finely characterize gluten whose properties depend on the composition of storage proteins but also on their concentration. Programs related to hypersensitivity should lead to the identification of gluten characteristics correlated to its digestibility. For these traits, a study is conducted to estimate the genetic part, the environmental part and the part of genotype x environment interactions on their variation (in collaboration with Arvalis and the industry). In addition, a study of genetic determinism is being undertaken. The final objective of this work will be to provide breeders with elements to improve gluten digestibility.

DNA-protein interaction networks identified to date in wheat (from Conlan et al., 1999; Albani et al., 1997; Ravel et al., 2014; Guo et al., 2015; Sun et al., 2017; Boudet et al., 2019). The names of cis-motifs (rectangles) and transcription factors (circles) are given.