Yahyaa, M., Newe Ya'ar Research Center, Agriculture Research Organization, Post Office Box 1021, Ramat Yishay, Israel
Tholl, D., Department of Biological Sciences, Virginia Polytechnic Institute and State University, 409 Latham Hall, 220 Agquad Lane, Blacksburg, VA, United States
Cormier, G., Department of Biological Sciences, Virginia Polytechnic Institute and State University, 119 Life Sciences I, 970 Washington Street, Blacksburg, VA, United States
Jensen, R., Department of Biological Sciences, Virginia Polytechnic Institute and State University, 119 Life Sciences I, 970 Washington Street, Blacksburg, VA, United States
Simon, P.W., Vegetable Crops Research Unit, Department of Horticulture, University of Wisconsin - Madison, 1575 Linden Drive, Madison, WI, United States
Ibdah, M., Newe Ya'ar Research Center, Agriculture Research Organization, Post Office Box 1021, Ramat Yishay, Israel

Plants produce an excess of volatile organic compounds, which are important in determining the quality and nutraceutical properties of fruit and root crops, including the taste and aroma of carrots (Daucus carota L.). A combined chemical, biochemical, and molecular study was conducted to evaluate the differential accumulation of volatile terpenes in a diverse collection of fresh carrots (D. carota L.). Here, we report on a transcriptome-based identification and functional characterization of two carrot terpene synthases, the sesquiterpene synthase, DcTPS1, and the monoterpene synthase, DcTPS2. Recombinant DcTPS1 protein produces mainly (E)-β-caryophyllene, the predominant sesquiterpene in carrot roots, and α-humulene, while recombinant DcTPS2 functions as a monoterpene synthase with geraniol as the main product. Both genes are differentially transcribed in different cultivars and during carrot root development. Our results suggest a role for DcTPS genes in carrot aroma biosynthesis. © 2015 American Chemical Society.