|YAHYAA, MOSAAB - Agricultural Research Organization Of Israel|
|THOLL, DOROTHEA - Virginia Polytechnic Institution & State University|
|CORMIER, GUY - Virginia Polytechnic Institution & State University|
|JENSEN, RODERICK - Virginia Polytechnic Institution & State University|
|IBDAH, MWAFAQ - Agricultural Research Organization Of Israel|
Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/30/2015
Publication Date: 4/30/2015
Publication URL: http://handle.nal.usda.gov/10113/61669
Citation: Yahyaa, M., Tholl, D., Cormier, G., Jensen, R., Simon, P.W., Ibdah, M. 2015. Identification and characterization of terpene synthases potentially involved in the formation of volatile terpenes in carrot (Daucus carota L.) roots. Journal of Agricultural and Food Chemistry. 63(19):4870-4878. doi: 10.1021/acs.jafc.5b00546.
Interpretive Summary: Volatile terpenoids account for the distinctive flavor of carrots and consequently are important in consumer quality. The enzymes that generate carrot terpenoids are not well-characterized. In this study we evaluated the collection of RNA molecules that are the blueprint for enzymes in carrot roots and determined that carrots with different flavor intensity have different quantities of RNAs that code for terpene biosynthetic enzymes. This research is of interest for flavor chemists, plant scientists, and consumer quality scientists.
Technical Abstract: Plants produce numerous volatile organic compounds, which are important in determining the quality and nutraceutical properties of fruit and root crops, including the taste and the 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 (Daucus 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)-ß-caryophyllene, the predominant sesquiterpene in carrot roots, and a-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 DcTPSs in carrot aroma biosynthesis.