Journal Article

Simultaneous editing of three homoeoalleles in hexaploid bread wheat confers heritable resistance to powdery mildew

Shan, Qiwei, Cheng, Xi, Qiu, Jin-Long, Wang, Yanpeng, Liu, Jinxing, Zhang, Yi, Gao, Caixia

2014

Overview

TALEN-induced mutation of all homologous copies of a gene that represses resistance to an important wheat pathogen confers a trait that has eluded plant breeders for decades. Sequence-specific nucleases have been applied to engineer targeted modifications in polyploid genomes 1 , but simultaneous modification of multiple homoeoalleles has not been reported. Here we use transcription activator–like effector nuclease (TALEN) 2 , 3 and clustered, regularly interspaced, short palindromic repeats (CRISPR)-Cas9 (refs. 4 , 5 ) technologies in hexaploid bread wheat to introduce targeted mutations in the three homoeoalleles that encode MILDEW-RESISTANCE LOCUS (MLO) proteins 6 . Genetic redundancy has prevented evaluation of whether mutation of all three MLO alleles in bread wheat might confer resistance to powdery mildew, a trait not found in natural populations 7 . We show that TALEN-induced mutation of all three TaMLO homoeologs in the same plant confers heritable broad-spectrum resistance to powdery mildew. We further use CRISPR-Cas9 technology to generate transgenic wheat plants that carry mutations in the TaMLO-A1 allele. We also demonstrate the feasibility of engineering targeted DNA insertion in bread wheat through nonhomologous end joining of the double-strand breaks caused by TALENs. Our findings provide a methodological framework to improve polyploid crops.

• Publisher: Nature Publishing Group US,Nature Publishing Group
• Subject: 38 / 42 / 45 / 49 / 631/61/447/2311 / Agriculture / Airborne microorganisms / Alleles / Allelomorphism / Ascomycota - genetics / Ascomycota - pathogenicity / Base Sequence / Bioinformatics / Biomedical Engineering/Biotechnology / Biomedicine / Biotechnology / Bread / CRISPR / Deoxyribonucleic acid / Diseases and pests / DNA / Genes / Genetic aspects / Genome editing / Genomes / Health aspects / letter / Life Sciences / Mildew / Molecular Sequence Data / Mutation / Natural populations / Nuclease / Pathogens / Plant breeding / Plant immunology / Polyploidy / Powdery mildew / Proteins / RNA Editing / Sequence Homology, Nucleic Acid / Transcription activator-like effector nucleases / Transgenic plants / Triticum - genetics / Triticum - microbiology / Triticum aestivum / Wheat