Identification of cucurbitacins and assembly of a draft genome for Aquilaria agallocha

Abstract

BackgroundAgarwood is derived from Aquilaria trees, the trade of which has come under strict control with a listing in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora. Many secondary metabolites of agarwood are known to have medicinal value to humans, including compounds that have been shown to elicit sedative effects and exhibit anti-cancer properties. However, little is known about the genome, transcriptome, and the biosynthetic pathways responsible for producing such secondary metabolites in agarwood.ResultsIn this study, we present a draft genome and a putative pathway for cucurbitacin E and I, compounds with known medicinal value, from in vitro Aquilaria agallocha agarwood. DNA and RNA data are utilized to annotate many genes and protein functions in the draft genome. The expression changes for cucurbitacin E and I are shown to be consistent with known responses of A. agallocha to biotic stress and a set of homologous genes in Arabidopsis thaliana related to cucurbitacin bio-synthesis is presented and validated through qRT-PCR.ConclusionsThis study is the first attempt to identify cucurbitacin E and I from in vitro agarwood and the first draft genome for any species of Aquilaria. The results of this study will aid in future investigations of secondary metabolite pathways in Aquilaria and other non-model medicinal plants.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2164-15-578) contains supplementary material, which is available to authorized users.

Confirmation of bioactivities of active ingredients of nemarioc-AL and nemafric-BL phytonematicides

“…Cucurbitacin A (C 32 H 46 O 8 ) and cucurbitacin B (C 32 H 46 O 9 ) are tetracyclic triterpenoids (Chen et al 2005), synthesised by the mevalonic acid pathway (Chen et al 2014). The water-soluble cucurbitacin A is unstable and oxidises to cucumin (C 27 H 40 O 9 ) and leptodermin (C 27 H 38 O 8 ), which had been shown to have both insect repellent and insecticidal activities (Damalas 2011;Gobinda et al 2014).…”

iTRAQ‐Based Quantitative Proteomic Analysis of Chemically Induced Aquilaria sinensis Provides Insights into Agarwood Formation Mechanism

“…And the genes related to terpenoid biosynthesis in wounded stems of A. malaccensis was also investigated by transcriptome sequencing, which demonstrated the upregulation of the expression of genes involved in terpenoid biosynthesis after wounding . The draft genome of A. agallocha was used to identify the genes related to cucurbitacin biosynthesis, which is the first report on the draft genome for any species of Aquilaria …”

Molecular Mechanism Studies of Terpenoid Biosynthesis in Agarwood

“…In a more recent research, in vitro materials from Aquilaria agallocha were found to contain abundant amounts of triterpene cucurbitacin I and E (Chen et al 2014 ). Although the true identity of the A. agallocha species is dubious as it is a synonym of Aquilaria malaccensis , nevertheless the assembled draft of its genome contributes to sequence information on Aquilaria , which is currently lacking.…”