Comparison of Mutation Rates in Soybean Following Transformation, Mutagenesis, Tissue Culture, and Conventional Breeding

This study will provide a comparative examination of the types and frequency of heritable genomic changes induced by tissue culture, transgene insertion, chemical mutagenesis, and irradiation mutagenesis, compared to the genetic variation already present in soybean breeding lines. Genetic engineering approaches such as tissue culture or transgene insertion are expected to induce heritable changes in a plant genome, but it is unclear if these changes differ in their nature or frequency from changes induced by mutagenesis, a widely used approach to generate variants useful for crop improvement. The goals of this study are to: 1) assess the type and frequency of mutation in genetically transformed plants relative to plants modified by other means, and 2) to assess the degree of change in gene expression caused by transformation relative to those induced by mutagenesis. A whole genome sequencing approach applied to 20 lines each for six treatments will provide the most complete assessment to date of the nature of genetic changes associated with genetic engineering and mutagenic approaches commonly applied to crop improvement.