Biomarkers and gene copy number variation for terpenoid traits associated with insect resistance in Sitka spruce : an integrated genomic, proteomic, and biochemical anaysis of (+)-3-carene biosynthesis
Date
2011-09-13
Authors
Bohlmann, Joerg
Hall, Dawn
Robert, Jeanne
Keeling, Christopher
Domanski, Dominik
Quesada, Alfonso Lara
Jancsik, Sharon
Hamberger, Britta
Borchers, Christoph
Kuzyk, Michael
Journal Title
Journal ISSN
Volume Title
Publisher
BioMed Central
Abstract
Conifers have evolved complex chemical defenses in the
form of oleoresin terpenoids to resist attack from pathogens
and herbivores. The large diversity of terpenoid
metabolites is determined by the size and composition
of the terpene synthase (TPS) gene family, and the single-
and multi-product profiles of these enzymes. The
monoterpene (+)-3-carene is associated with resistance
of Sitka spruce (Picea sitchensis) to white pine weevil
(Pissodes strobi). We used a combined genomic, proteomic
and biochemical approach to analyze the (+)-3-carene
phenotype in two contrasting Sitka spruce
genotypes. Resistant trees produced significantly higher
levels of (+)-3-carene than susceptible trees, in which
only trace amounts were detected. Biosynthesis of (+)-3-
carene is controlled, at the genome level, by a small
family of closely related (82-95% amino acid sequence
identity) (+)-3-carene synthase (PsTPS-3car) genes.
Transcript profiling identified one PsTPS-3car gene
(PsTPS-3car1) which is expressed in both genotypes,
one gene (PsTPS-3car2) expressed only in resistant
trees, and one gene (PsTPS-3car3) expressed only in
susceptible trees. The PsTPS-3car2 gene was not
detected in genomic DNA of susceptible trees. Targetspecific
selected reaction monitoring substantiated this
pattern of differential expression of members of the
PsTPS-3car family on the proteome level. Kinetic
characterization of the recombinant PsTPS-3car
enzymes identified differences in the activities of PsTPS-
3car2 and PsTPS-3car3as a factor for the different
(+)-3-carene profiles of resistant and susceptible trees.
In conclusion, variation of the (+)-3-carene phenotype is
controlled by PsTPS-3car gene copy number variation,
variation of gene and protein expression, and variation
of catalytic efficiencies.
Description
BioMed Central
Keywords
Citation
Bohlmann et al.: Biomarkers and gene copy number variation for terpenoid traits associated with insect resistance in Sitka spruce: An integrated genomic, proteomic, and biochemical analysis of (+)-3-carene biosynthesis. BMC Proceedings 2011 5(Suppl 7):O27.