The Potential of Genome Editing for Breeding Durum Wheat

The applications of genome editing (GE) technologies in wheat is constantly increasing, but less frequently applied to durum wheat compared to bread wheat. Durum wheat, which accounts for about 5–8% of the world wheat production, attracts less interest from breeders and researchers, likely due to the narrower diffusion of its cultivation. At the same time, it has good nutritional value and is adaptable to poor soils, therefore durum wheat could represent a source of genetic variability for introducing new traits and genes into bread wheat. Despite the challenges of applying GE technologies in wheat, which mostly arise from the transformation and regeneration efficiency and the high genomic redundancy due to polyploidy, many applications have been reported for yield enhancement, improvement of grain quality, and increased resilience to biotic/abiotic stress. Alternative methods, including CRISPR systems and delivery strategies, are being developed to overcome limitations such as slow protocols, genotype recalcitrance, and transgene integration in the host genome. The exploration of various CRISPR variants for different types of genetic modifications and fine regulation of gene expression allow a more precise and efficient site-directed mutagenesis of complex genomes, helping researchers and breeders modify homoeologous genes to produce specific phenotypes. GE, including CRISPR/Cas systems, offers the opportunity to deepen knowledge of the molecular mechanisms underlying wheat productivity, quality, and resilience to abiotic/biotic stress. Due to its accuracy and effectiveness, GE is deeply transforming research and breeding for agriculture with even more application for commercial crop/wheat improvement.