Project description:Termites produce the most diverse array of terpenoids among metazoans, comprising over 200 structures involved in chemical communication and defense described to date, some of which are exclusive to termites. However, their biosynthesis has not yet been elucidated, and the responsible terpene synthases remain unknown. Here, we draw lessons from discoveries in other insects which showed that terpene synthases can originate through duplications and neofunctionalizations of isoprenyl diphosphate synthase genes, occurring independently in individual clades. We identify a novel gene family which arose through the duplication of geranylgeranyl pyrophosphate synthase (GGPPS) in the common ancestor of Neoisoptera, the modern terpene-producing termite lineage. This family subsequently expanded into multiple paralogs and has been retained in neoisopteran genomes throughout 100 million years of diversification. We functionally characterized several GGPPS-like enzymes from two neoisopteran species and demonstrated that they indeed act as terpene synthases generating biologically relevant sesqui- and diterpenes. In Embiratermes neotenicus, EneoC produces enantiomerically pure (3R,6E)-nerolidol, known as the queen pheromone, and EneoE produces (E,E,E)-neocembrene, another queen-specific compound. In Nasutitermes takasagoensis, NtGGPPS6 synthesizes (E,E,E)-neocembrene, the precursor of polycyclic diterpenes characteristic of this genus. We explore the evolutionary transition from isoprenyl diphosphate synthase to terpene synthase activity in these enzymes in terms of structural features and selection pressures, and highlight the potential role of transposable elements in the evolution of the GGPPS-like family. We conclude that we have identified an enzyme family underlying the remarkable richness of termite terpenoids, which likely contributed to the ecological success of Neoisoptera
Project description:Fennel (Foeniculum vulgare Mill.) is an aromatic herb cultivated worldwide. Narrow-wavelength red LED light can potentially regulate the accumulation of secondary metabolites such as aroma compounds for crops, but its impact on fennel aroma remains unclear. This study investigated supplemental red LED effects on fennel aroma using nutrient film hydroponic systems, comparing natural greenhouse light (control) with supplemental red LED (100 μmol·m-2·s-1, 14h·d-1). GC-MS-O characterized aroma compounds in fresh fennel while RNA-seq analyzed gene expression. Supplemental red LED was found to enhance growth (height, fresh biomass) and significantly increase aroma-active compounds in leaves, particularly phenylpropanoids like (E)-anethole and estragole. RNA-seq revealed 1958 upregulated and 278 downregulated genes. Under supplemental red light conditions, several phenylpropanoid biosynthesis genes were regulated, including eugenol synthase and isoeugenol synthase; related transcripts were also identified as differentially expressed. Results demonstrated the potential application of LED lighting for enhancing culinary herb quality in controlled environments and providing some molecular insights for fennel aroma biosynthesis.
Project description:MicroRNAs (miRNAs) are essential small RNA molecules that regulate the expression of target mRNAs in plants and animals. Here, we aimed to identify miRNAs and their putative targets in Hibiscus syriacus, the national flower of South Korea. Therefore, we employed high-throughput sequencing of small RNAs obtained from four different tissues (i.e., leaf, root, flower, and ovary) and identified 33 conserved and 30 novel miRNA families, many of which showed differential tissue-specific expressions. In addition, we computationally predicted novel targets of miRNAs and validated some of them using 5′ rapid amplification of cDNA ends analysis. One of the validated novel targets of miR477 was a terpene synthase, the primary gene involved in the formation of disease-resistant terpene metabolites such as sterols and phytoalexins. In addition, a predicted target of conserved miRNAs, miR396, is SHORT VEGETATIVE PHASE, which is involved in flower initiation and is duplicated in Hibiscus syriacus. Collectively, this study provides the first reliable draft of the Hibiscus syriacus miRNA transcriptome that should constitute a basis for understanding the biological roles of miRNAs in Hibiscus syriacus.
2017-09-08 | GSE99329 | GEO
Project description:Terpene synthase gene amplicons from subseafloor sediments
Project description:In Crohn's disease, creeping fat is the characteristic expansion of mesenteric adipose tissue wrapping around the inflamed intestine. Through a comparative transcriptomic analysis of creeping fat and normal-looking mesenteric adipose tissues from patients with Crohn's disease and non-Crohn's disease, we found that a dynamic transcriptional and cell compositional change occurs during the progression from non-Crohn's disease to Crohn's disease, and finally to creeping fat.