Publications

• Functional characterization of three Coffea arabica L. monoterpene synthases: insights into the enzymatic machinery of coffee aroma.

  Del Terra L., Lonzarich V., Asquini E., Navarini L., Graziosi G., Suggi Liverani F., Pallavicini A.

  The chemical composition of the coffee beverage is extremely complex, being made up of hundreds of volatile and non-volatile compounds, many of which are generated in the thermal reactions that occur during the roasting process. However, in the raw coffee bean there are also compounds that survive ... >> More

  The chemical composition of the coffee beverage is extremely complex, being made up of hundreds of volatile and non-volatile compounds, many of which are generated in the thermal reactions that occur during the roasting process. However, in the raw coffee bean there are also compounds that survive roasting and are therefore extracted into the beverage. Monoterpenes are an example of this category, as their presence has been reported in the coffee flower, fruit, seed, roasted bean and in the beverage aroma. The present work describes the isolation, heterologous expression and functional characterization of three Coffea arabica cDNAs coding for monoterpene synthases. RNA was purified from C. arabica (cv. Catuai Red) flowers, seeds and fruits at 4 successive ripening stages. Degenerate primers were designed on the most conserved regions of the monoterpene synthase gene family, and then used to isolate monoterpene synthase-like sequences from the cDNA libraries. After 5'- and 3'-RACE, the complete transcripts of 4 putative C. arabica monoterpene synthases (CofarTPS) were obtained. Gene expression in different tissues and developmental stages was analysed. After heterologous expression in Escherichia coli, enzyme activity and substrate specificity were evaluated in vitro by incubation of the recombinant proteins with geranyl pyrophosphate (GPP), geranylgeranyl pyrophosphate (GGPP) and farnesyl pyrophosphate (FPP), precursors respectively of mono-, di- and sesquiterpenes. The reaction products were characterized by HS-SPME GC-MS. CofarTPS1 was classified as a limonene synthase gene, while CofarTPS2 and 3 showed lower activity with the production of linalool and β-myrcene. << Less

  Phytochemistry 89:6-14(2013) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• Geraniol and linalool synthases from wild species of perilla.

  Masumoto N., Korin M., Ito M.

  Geraniol and linalool synthases were isolated from three pure strains of Perilla hirtella and Perilla setoyensis, which are wild species of perilla. Their amino acid sequences were very similar to those of Perilla citriodora and Perilla frutescens that were reported previously. However, comparison ... >> More

  Geraniol and linalool synthases were isolated from three pure strains of Perilla hirtella and Perilla setoyensis, which are wild species of perilla. Their amino acid sequences were very similar to those of Perilla citriodora and Perilla frutescens that were reported previously. However, comparison of the sequences of the same functional synthases derived from different species of Perilla demonstrated that the similarities were high among P. citriodora, P. hirtella and P. frutescens, but low between P. setoyensis and any of the others. This result corresponds well with our previous results showing that P. setoyensis is remotely related to the other perilla species. Both geraniol and linalool synthases utilize geranyl diphosphate (GDP) as their catalytic substrate and they were expressed simultaneously in perilla. The linalool synthase is considered to be the enzyme whose metabolite seems not to be oxidized nor reduced in the plant body and the geraniol and limonene synthases are the initial-step-catalyzing enzymes for a variety of oil compounds. The regulation of the substrate flow between them would be interesting for further study. << Less

  Phytochemistry 71:1068-1075(2010) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• Novel family of terpene synthases evolved from trans-isoprenyl diphosphate synthases in a flea beetle.

  Beran F., Rahfeld P., Luck K., Nagel R., Vogel H., Wielsch N., Irmisch S., Ramasamy S., Gershenzon J., Heckel D.G., Kollner T.G.

  Sesquiterpenes play important roles in insect communication, for example as pheromones. However, no sesquiterpene synthases, the enzymes involved in construction of the basic carbon skeleton, have been identified in insects to date. We investigated the biosynthesis of the sesquiterpene (6R,7S)-him ... >> More

  Sesquiterpenes play important roles in insect communication, for example as pheromones. However, no sesquiterpene synthases, the enzymes involved in construction of the basic carbon skeleton, have been identified in insects to date. We investigated the biosynthesis of the sesquiterpene (6R,7S)-himachala-9,11-diene in the crucifer flea beetle Phyllotreta striolata, a compound previously identified as a male-produced aggregation pheromone in several Phyllotreta species. A (6R,7S)-himachala-9,11-diene-producing sesquiterpene synthase activity was detected in crude beetle protein extracts, but only when (Z,E)-farnesyl diphosphate [(Z,E)-FPP] was offered as a substrate. No sequences resembling sesquiterpene synthases from plants, fungi, or bacteria were found in the P. striolata transcriptome, but we identified nine divergent putative trans-isoprenyl diphosphate synthase (trans-IDS) transcripts. Four of these putative trans-IDSs exhibited terpene synthase (TPS) activity when heterologously expressed. Recombinant PsTPS1 converted (Z,E)-FPP to (6R,7S)-himachala-9,11-diene and other sesquiterpenes observed in beetle extracts. RNAi-mediated knockdown of PsTPS1 mRNA in P. striolata males led to reduced emission of aggregation pheromone, confirming a significant role of PsTPS1 in pheromone biosynthesis. Two expressed enzymes showed genuine IDS activity, with PsIDS1 synthesizing (E,E)-FPP, whereas PsIDS3 produced neryl diphosphate, (Z,Z)-FPP, and (Z,E)-FPP. In a phylogenetic analysis, the PsTPS enzymes and PsIDS3 were clearly separated from a clade of known coleopteran trans-IDS enzymes including PsIDS1 and PsIDS2. However, the exon-intron structures of IDS and TPS genes in P. striolata are conserved, suggesting that this TPS gene family evolved from trans-IDS ancestors. << Less

  Proc Natl Acad Sci U S A 113:2922-2927(2016) [PubMed] [EuropePMC]

  This publication is cited by 17 other entries.