ENAapplication/xmlftp.sra.ebi.ac.uk/vol1/fastq/SRR114/050/SRR11413150/SRR11413150.fastq.gzprimaryOK200GenomicsNanjing Agricultural Universityhttps://www.ebi.ac.uk/ena/browser/view/PRJNA615073Clematis florida is a popular ornamental vine species known for diverse colors and shapes of flowers but not for scent. Here we investigated the composition and biosynthesis of floral scent in Kaiser, a fragrant cultivar of C. florida that has sterile flowers. Through volatile profiling, flowers of Kaiser were found to emit more than 20 compounds with monoterpenes being most abundant. Among the three floral organs, namely sepals, transformed-petals and ovaries, ovaries had the highest rates of total volatile emission. To determine the molecular mechanism underlying floral scent biosynthesis in Kaiser, we created a transcriptome of Kaiser flowers and searched the transcriptome for terpene synthase genes (TPSs), which are key genes for terpene biosynthesis. Among the TPS genes identified, three were putative intact full-length genes and were designated CfTPS1, CfTPS2, and CfTPS3. Phylogenetic analysis placed CfTPS1, CfTPS2, and CfTPS3 to the TPS-g, TPS-b, and TPS-a subfamily, respectively. Through in vitro enzyme assays with Escherichia coli-expressed recombinant proteins, both CfTPS1 and CfTPS2 were demonstrated to catalyze the conversion of geranyl diphosphate to linalool, the most abundant constituent of C. florida floral scent. In addition, they both produced the sesquiterpene nerolidol from farnesyl diphosphate. CfTPS3 showed sesquiterpene synthase activity producing multiple products. All three CfTPS genes showed higher levels of expression in sepals than those in transformed-petals and ovaries. Our results show that despite being sterile, the flowers of Kaiser have normal mechanisms for floral scent biosynthesis that make the flowers fragrant.ENAPetals, Reproductive, sterility, Stigma, Plant Sepal, Carpal, bioformation, Infertile, Pflanze, Plant Anthers, Calyx, Ovary, Plant Carpals, biosynthesis, infertile, Calyxs, compositionality, Plant Stigmas, composed of, Pistils, Filament, Plant Style, Sterile, Sepal, Plant Corollas, Ovaries, Plant Bloom, Carpals, Infertile (finding), Stigmas, Plant Styles, infertility disorder, Blooms, Plant Blooms, sterile, Plant Carpal, Bloom, Plant Ovaries, Flower Filament, multicellular organismal biosynthetic process, Styles, plantae, Anther, single-organism biosynthetic process, formation, Plant Corolla, anabolism, Plant Ovary, content, Sepals, Plant, Flower Filaments, Plant Calyxs, composition, Filaments, Plant Calyx, Style, Plant Anther, Pistil, Corolla, synthesis, Flower, Corollas, Stamen, Plant Stigma, Plant Stamens, infertility, Sterility, Reproductive Sterility, Plant Petals, structure, Plant Sepals, Plant Petal, Blossoms, Plant Stamen, Anthers, fertility disorders, Blossom, Stamens, viridiplantae., Petal0.00.00.00.00.0falseComposition and Biosynthesis of Scent Compounds from Sterile Flowers of an Ornamental Plant Clematis florida cv Kaiser2022-05-312020-05-06PRJNA615073231648