Title: | "Oleoresin defenses in conifers: chemical diversity, terpene synthases and limitations of oleoresin defense under climate change" |
Address: | "Michael Smith Laboratories, University of British Columbia, 301-2185 East Mall, Vancouver, BC, V6T 1Z4, Canada" |
ISSN/ISBN: | 1469-8137 (Electronic) 0028-646X (Linking) |
Abstract: | "Conifers have evolved complex oleoresin terpene defenses against herbivores and pathogens. In co-evolved bark beetles, conifer terpenes also serve chemo-ecological functions as pheromone precursors, chemical barcodes for host identification, or nutrients for insect-associated microbiomes. We highlight the genomic, molecular and biochemical underpinnings of the large chemical space of conifer oleoresin terpenes and volatiles. Conifer terpenes are predominantly the products of the conifer terpene synthase (TPS) gene family. Terpene diversity is increased by cytochromes P450 of the CYP720B class. Many conifer TPS are multiproduct enzymes. Multisubstrate CYP720B enzymes catalyse multistep oxidations. We summarise known terpenoid gene functions in various different conifer species with reference to the annotated terpenoid gene space in a spruce genome. Overall, biosynthesis of terpene diversity in conifers is achieved through a system of biochemical radiation and metabolic grids. Expression of TPS and CYP720B genes can be specific to individual cell types of constitutive or traumatic resin duct systems. Induced terpenoid transcriptomes in resin duct cells lead to dynamic changes of terpene composition and quantity to fend off herbivores and pathogens. While terpenoid defenses have contributed much to the evolutionary success of conifers, under new conditions of climate change, these defences may become inconsequential against range-expanding forest pests" |
Keywords: | "Alkyl and Aryl Transferases/genetics/*metabolism Animals Climate Change Coleoptera Cytochrome P-450 Enzyme System/metabolism Gene Expression Regulation, Plant *Herbivory Phylogeny Plant Extracts/chemistry/*metabolism Terpenes/metabolism Tracheophyta/*chem;" |
Notes: | "MedlineCeledon, Jose M Bohlmann, Jorg eng Research Support, Non-U.S. Gov't Review England 2019/06/11 New Phytol. 2019 Dec; 224(4):1444-1463. doi: 10.1111/nph.15984. Epub 2019 Jul 16" |