The present disclosure provides compositions and methods for altering gibberellin (GA) content in corn or other cereal plants. Methods and compositions are also provided for altering the expression of genes related to gibberellin biosynthesis through editing of specific subtypes of GA20 oxidase genes to introduce an antisense sequence or segment into the gene. Modified plant cells and plants having a dominant allele reducing the expression or activity of one or more GA oxidase genes are further provided comprising reduced gibberellin levels and improved characteristics, such as reduced plant height and increased lodging resistance, but without off-types.