Résumé
Sorghum is the world’s 5th most important grain crop. Its ability to cope with biotic and abiotic constraintscould allow it to contribute to global food security in the context of climate change. However, the lowdigestibility of the grain reserve proteins (called kafirins) by gastrointestinal proteases is hampering itswider use for food and feed. The structure of the protein bodies in which are stored the kafirins is potentiallyresponsible of this defect. The molecular mechanisms underlying the development and modification ofkafirin-containing protein bodies are still largely unknown. In this context, our objective is to decipher themolecular mechanisms involved in the regulation of the content and digestibility of sorghum grain reserveproteins. The evolution of the transcriptome was monitored during the grain development of the Maciagenotype, and supplemented by an analysis of gene co-expression networks (GCN). In parallel, the proteincontent of the grains and their in vitro digestibility were measured. Analyses of allowed the identificationof transcription factors (TFs) potentially regulating the mechanisms of protein reserve establishment. Weidentified co-expression modules involving kafirin genes and genes orthologs to TFs already known inmaize, rice and arabidopsis. In those modules, we also identified not yet identified TFs. In the future, weplan to evaluate the role of these TFs by a simplified cellular overexpression system in sorghum protoplasts.