Role of genome engineering for the development of resistant starch-rich, allergen-free and processing quality improved cereal crops

Cereals are the most important staple food crop in the world, contributing substantially to more than 50% of daily caloric and nutrient intake across the globe. They are a significant source of starch, protein, dietary fiber, vitamins, minerals and phytochemicals, which are then further processed into various end-use food products. The processing and nutrition quality of cereal grains is largely dependent upon the molecular and physico-chemical characteristics of these components which, in turn, alter organoleptic properties and digestibility, hence consumer acceptability. For example, cereals with "high-resistant starch" and "allergen-free" properties reduce the risk of diet-related disease and food allergies which are now more prevalent worldwide. An improvement of processing quality, together with associated traits in cereal grains must be targeted for the manufacturing of a wide range of food products derived from it. The genetic gain and understanding of molecular basis of cereal grain quality through regulatory structural genes, chemical and metabolic pathways have been extensively studied using various genetics and biotechnological approaches. Recent advances in targeted genome-editing, mutagenesis, use of tissue/stages-specific promoters and genome-wide association genetics, reveal molecular mechanisms underlying improved processing and nutritional quality of cereal crops. In this chapter, we integrate the knowledge from different multi-omics and genetic-based studies that have been successfully employed to discuss how these techniques are influencing the quality and nutritional traits in cereal grains and their general acceptance in downstream processes.