Editing the Wheat Genome for Disease Resistance

Sequence-specific nucleases (SSNs) are emerging as new tools for engineering targeted modifications in genomes. However, their effectiveness in polyploid plant species has not been well tested. Here, we demonstrate that both TALEN and CRISPR/Cas9 are efficient at mutating genes in hexaploid wheat, the world’s most important crop, but frequently recalcitrant to conventional genetic manipulation. We show that TALEN-induced mutations in three TaMLO homoeologs are faithfully inherited, and that simultaneous mutation of all three TaMLO homoeologs confers broad spectrum resistance to powdery mildew, a resistance trait that has not been found in the natural population. Furthermore, we prove the feasibility of engineering targeted DNA insertion through non-homologous end joining of the double strand breaks caused by TALENs. Our work provides a methodological framework for genome engineering in polyploid plants, and will likely stimulate the application of SSN-based genome editing technologies for genetic improvement of bread wheat and other polyploid crops.