Fuente: WIPO "tomato" Compositions and methods for modifying genomic DNA sequences of a plant cell are provided. The methods produce double stranded breaks at target sites in a genomic DNA sequence, resulting in mutation, insertion, and/or deletion of DNA sequences at the target site(s) in a genome. The compositions comprise nucleic acid constructs comprising nucleotide sequences that encode a Cas12a protein. The nucleic acid constructs can be used to direct the modification of genomic DNA at a target site. Methods to use these DNA constructs to modify genomic DNA sequences are also provided.