In vivo function of Pgβglu-1 in the release of acetophenones in white spruce

Melissa H Mageroy; Denis Lachance; Sharon Jancsik; Geneviève Parent; Armand Séguin; John Mackay; Joerg Bohlmann

doi:10.7717/peerj.3535

In vivo function of Pgβglu-1 in the release of acetophenones in white spruce

PeerJ. 2017 Jul 7:5:e3535. doi: 10.7717/peerj.3535. eCollection 2017.

Authors

Melissa H Mageroy^{1

2}, Denis Lachance³, Sharon Jancsik¹, Geneviève Parent^{4

5}, Armand Séguin³, John Mackay^{4

5}, Joerg Bohlmann^{1

6

7}

Affiliations

¹ Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada.
² Norwegian Institute of Bioeconomy Research, Aas, Norway.
³ Laurentian Forestry Centre, Natural Resources Canada, Quebec, Canada.
⁴ Department of Wood and Forest Sciences, Laval University, Quebec, Canada.
⁵ Department of Plant Sciences, University of Oxford, Oxford, United Kingdom.
⁶ Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, British Columbia, Canada.
⁷ Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada.

Abstract

Eastern spruce budworm (Choristoneura fumiferiana Clemens) (ESBW) is a major forest pest which feeds on young shoots of white spruce (Picea glauca) and can cause landscape level economic and ecological losses. Release of acetophenone metabolites, piceol and pungenol, from their corresponding glycosides, picein and pungenin, can confer natural resistance of spruce to ESBW. A beta-glucosidase gene, Pgβglu-1, was recently discovered and the encoded enzyme was characterized in vitro to function in the release of the defensive acetophenone aglycons. Here we describe overexpression of Pgβglu-1 in a white spruce genotype whose metabolome contains the glucosylated acetophenones, but no detectable amounts of the aglycons. Transgenic overexpression of Pgβglu-1 resulted in release of the acetophenone aglycons in planta. This work provides in vivo evidence for the function of Pgβglu-1.

Keywords: Beta-glucosidase; Conifer defense; Picea glauca; Spruce budworm; Transgenic spruce.

Grants and funding

The work was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC; Strategic Project Grant to JB and JM and Discovery Grant to JB); the Genomics R&D Strategy of Canada (to AS); and funds received through Genome Canada, Genome British Columbia and Genome Quebec for the SMarTForests Project (to JB and JM) and the Spruce-Up (243FOR) Project (to JB). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.