Development and optimization of a Barley stripe mosaic virus‐mediated gene editing system to improve Fusarium head blight resistance in wheat

Unfortunately, most wheat genotypes have extremely low callus induction and regeneration efficiency, which limits the application of genome editing in wheat breeding. [...]a new gRNA delivery system that bypasses the tissue culture is critical to the successful use of gene editing in wheat breeding. Lanes 4 and 6 are the vector control and two mutants with TaHRC-specific cleavage bands (768 and 298 bp). (d) and (e) Edited In/del sequences at TaPDS and TaHRC target sites of the mutants. (f) Seedlings of a TaPDS albino mutant (left) and TaHRC mutant. (g) Sequence of edited and non-edited TaHRC in Bobwhite showing insertions in Mut01 (57 bp) and Mut02 (3 bp). (h) and (i) FHB symptoms and percentages of symptomatic spikelets (PSS) between the mutants and control. (j) Sequences of edited and non-edited TaHRC in Everest. (k) and (l) PSS and infected spikes of mutants and control. (m) Recovery rates of TaHRC mutants generated using TaHRC_sgRNA, TaHRC_sgRNA-mTaFT and TaHRC_sgRNA-tRNAIleu vectors. To expand the utility of this editing system in other wheat cultivars with low transformation efficiency, we transferred the Cas9 gene into a locally adapted winter wheat cultivar 'Everest' by crossing Everest to a Cas9-OE Bobwhite plant and selecting Cas9-OE Everest F2 progeny that carried homozygous Cas9 and the target gene.