†Newe Ya'ar Research Center, Agriculture Research Organization, Post Office Box 1021, Ramat Yishay 30095, Israel.
‡Department of Biological Sciences, Virginia Polytechnic Institute and State University, 409 Latham Hall, 220 Agquad Lane, Blacksburg, Virginia 24061, United States.
J Agric Food Chem. 2015 May 20;63(19):4870-8. doi: 10.1021/acs.jafc.5b00546. Epub 2015 May 7.
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.
植物会产生过量的挥发性有机化合物，这些化合物对于确定水果和根茎作物（包括胡萝卜的味道和香气）的质量和营养特性非常重要。本研究采用化学、生化和分子联合分析的方法，对不同新鲜胡萝卜（D. carota L.）品种中挥发性萜类物质的差异积累进行了评估。本研究基于转录组鉴定并对两种胡萝卜萜烯合酶（倍半萜合酶 DcTPS1 和单萜合酶 DcTPS2）进行了功能表征。重组 DcTPS1 蛋白主要产生（E）-β-石竹烯，这是胡萝卜根中主要的倍半萜烯，还有 α-葎草烯；而重组 DcTPS2 作为单萜合酶，以香叶醇为主要产物。这两个基因在不同品种和胡萝卜根发育过程中呈现差异转录。本研究结果表明，DcTPS 基因在胡萝卜香气生物合成中发挥作用。
