Rapid generation of a transgene-free powdery mildew resistant tomato by genome deletion (OA)

Using a traditional breeding approach, introducing a single gene into a desirable cultivar requires repeated backcrossing. This lengthy process can be circumvented through genetic engineering (making transgenic plants), but consumer concerns and extensive, expensive regulatory hurdles have stifled many transgenic projects. New genome editing methods are likely to have fewer regulatory obstacles, so are a promising alternative for crop improvement. Nekrasov et al. have used a gene-editing approach to delete a gene (Mlo) that makes tomato plants susceptible to the fungus that causes powdery mildew. They produced transgene-free mildew-resistant varieties (with no off-site alterations) in less than a year. (Summary by Mary Williams) Sci. Rep. 10.1038/s41598-017-00578-x