Methods for efficient maize genome editing

A method of effecting in a Zea sp. nuclear genome at least one targeted modification of a first predetermined target site in a promoter region upstream of a transcription start site of a first gene and at least one targeted modification of a second predetermined target site in a promoter region upstream of a transcription start site of a second gene, wherein the targeted modifications result in a change of expression in the first gene and a change of expression in the second gene, wherein the targeted modifications comprise an insertion of a predetermined sequence encoded by a single stranded DNA polynucleotide donor molecule that does not have homology arms, wherein each targeted modification is achieved by integrating the predetermined sequence at a double-strand break (DSB) in the first and the second predetermined target sites by non-homologous end joining (NHEJ), wherein the predetermined sequence is integrated about 50 to about 500 nucleotides 5′ to the start codon of the coding sequence of the first and second gene, and wherein the predetermined sequence encoded by the single-stranded DNA polynucleotide donor molecule comprises a transcription factor recognition site sequence, thereby modifying the nuclear genome.