Whole genome duplications (WGD) are prevalent throughout Angiosperm evolution and contribute to shaping adaptive traits in plants. Gene expression is one phenotype that is immediately influenced by WGD. Gene expression is biased in many studied polyploids such that one subgenome maintains a higher global expression level over other(s). However, little is known about how this phenotype is affected, and potentially established, by environmental conditions experienced by recently formed polyploids. Although expression-level dominance has been characterized in many allopolyploid plant species, it is generally described from plants growing in uniform conditions, which is not representative of the expression landscape of plants growing in the wild or in different climates. Parental diploid species adapted to different environmental conditions may contribute differentially to the inherited expression profile in allopolyploids. However, it remains unclear whether subgenome expression shifts toward the more favored subgenome(s) relative to environmental conditions. Camelina sativa is a low-input oilseed crop suitable for food and biofuel production on otherwise unsuitable agricultural land. Its favorable seed fatty acid composition and quantity is amenable to aviation biofuel and represents a tractable, low-emission alternative for aviation. The crop has recent hybrid origins from two extant diploid species, C. hispida and C. neglecta, with a third subgenome derived from a taxon somewhat closely related to C. neglecta. As an allohexaploid, C. sativa’s genome contains the full genomic complements (subgenomes) from these diploid progenitors and transcribes their genes to perform necessary biological functions with the C. hispida subgenome showing expression-level dominance over the other two subgenomes. Growth trials in controlled environmental conditions were conducted to characterize the effect of growing temperature on subgenome dominance and to determine whether these changes correspond to transcriptional changes in the diploid parents. Further understanding the magnitude of this effect, and the potential mechanisms underlying it may lead to a more complete understanding of the establishment of subgenome dominance.