Mutation of the VInv 5' UTR regulatory region reduces acrylamide levels in processed potato to reach EU food-safety standards

Abstract

Protein-coding regions of genes have so far been the preferred targets for trait improvement using CRISPR-Cas9 genome editing in plants. Alteration of the reading frame can result in termination of transcription or translation, hence, loss of function of the encoded protein. 5 UTR sequences also represent a practical target region to alter gene expression and protein abundance. However, editing of 5 UTRs has so far been scarcely used to engineer trait in crop plants. Here, we demonstrate that insertion of a single adenine nucleotide mediated by Cas9 in the 5 UTR region of two alleles from the Vacuolar invertase gene (VInv) of the tetraploid potato variety Lady Rosetta (LaRo) is sufficient to substantially lower the content of reducing sugars in the potato under cold-storage conditions. Moreover, the acrylamide content generated during processing of the edited potato lines into crisps was more than three folds lower than the current EU-regulated maximum level of 750 g/kg in crisps. This gene-editing approach represents a durable strategy to improve food safety of potatoes in varieties widely preferred by the consumers and the industry.