The gene encoding the protein 1-aminocyclopropane-1-carboxylate synthase (ACC synthase) has been extensively studied in plant species because of its role in regulating the formation of the plant hormone, ethylene. Although the ACC synthase gene has been heavily studied in angiosperms, it has never been cloned from a gymnosperm species. This dissertation presents the cloning of a gene, PTACS-1, with high homology to ACC synthase, from Pinus taeda (loblolly pine), a commercially important tree in the southern U.S. Additionally, a shorter nearly identical transcript, PTACS-1s was identified. Expression of the PTACS-1 and PTACS-1s transcripts was measured using quantitative PCR in tissues throughout the tree, and in response to known elicitors of ACC synthase gene transcription. Further, the expression of PTACS-1 and PTACS-1s were monitored in response to known elicitors of compression wood, a reaction wood formed in gymnosperms. Putative roles for PTACS-1 in compression wood development are discussed.