%0 Journal Article
%T Transcriptome mining, functional characterization, and phylogeny of a large terpene synthase gene family in spruce (Picea spp.)
%A Christopher I Keeling
%A Sabrina Weisshaar
%A Steven G Ralph
%A Sharon Jancsik
%A Britta Hamberger
%A Harpreet K Dullat
%A J£¿rg Bohlmann
%J BMC Plant Biology
%D 2011
%I BioMed Central
%R 10.1186/1471-2229-11-43
%X The availability of extensive transcriptome resources in the form of expressed sequence tags (ESTs) and full-length cDNAs in several spruce (Picea) species allowed us to estimate that a conifer genome contains at least 69 unique and transcriptionally active TPS genes. This number is comparable to the number of TPSs found in any of the sequenced and well-annotated angiosperm genomes. We functionally characterized a total of 21 spruce TPSs: 12 from Sitka spruce (P. sitchensis), 5 from white spruce (P. glauca), and 4 from hybrid white spruce (P. glauca ¡Á P. engelmannii), which included 15 monoterpene synthases, 4 sesquiterpene synthases, and 2 diterpene synthases.The functional diversity of these characterized TPSs parallels the diversity of terpenoids found in the oleoresin and volatile emissions of Sitka spruce and provides a context for understanding this chemical diversity at the molecular and mechanistic levels. The comparative characterization of Sitka spruce and Norway spruce diterpene synthases revealed the natural occurrence of TPS sequence variants between closely related spruce species, confirming a previous prediction from site-directed mutagenesis and modelling.Conifer trees (order Coniferales; Gymnosperms) are extremely long-lived plants that must confront a multitude of biotic and abiotic stresses that vary with the season and over their lifetime. Conifers have evolved several resistance mechanisms that repel, kill, inhibit, or otherwise reduce the success of herbivores and pathogens. These mechanisms include both mechanical and chemical defences that can be present constitutively or that are induced upon challenge [1,2]. As a major part of their constitutive and inducible defensive repertoire, conifers produce an abundant and complex mixture of terpenoids in the form of oleoresin secretions and volatile emissions [2,3]. The diversity of the terpenoids in conifers suggests that, like in other plants [4], an arms race has unfolded in the interactions of c
%U http://www.biomedcentral.com/1471-2229/11/43