Dr. C. Peter Constabel

Dr. C. Peter Constabel
Centre for Forest Biology, Biology

BSc (Sask), MSc (UBC), PhD (UofM)

Area of expertise

Biochemistry, molecular biology, and ecology of herbivore defense and phenolic metabolism in trees


  • Plant biochemistry, genomics and molecular biology; chemical ecology and plant stress adaptation; bioactive phenolics and tannins

My research program aims to understand how plants use phytochemicals to defend against herbivores and pathogens and adapt to environmental stresses. Research in my lab focusses on plant tannins and other bioactive phenolic phytochemicals, which we study in poplar and aspen. We are interested in understanding how these are synthesized, regulated, and how they help adapt poplar trees to their environment.
A major advantage of studying these questions in Populus is that it can be genetically transformed, so that we can create transgenic poplar plants to test the functions of specific genes. We use the tools of biochemistry, molecular biology, genomics, and plant transformation to answer the following fundamental questions.

  • What is the adaptive role of tannins in trees, in particular in roots? Are they important for pathogen defense or mycorrhizal interactions?
  • How do MYB and other transcription factors regulate biosynthesis of tannins and other phenolics? What is the impact of MYB knock-outs on tannin accumulation and tree adaptation?
  • How are the salicinoid phenolic glycosides synthesized? Can we identify enzymes for this as yet unelucidated pathway?

My lab has also studied phenolic plant chemicals in red alder, which synthesize diarylheptanoid phenolics. We have also studied the synthesis and functions of tannins in fruit, in particular in blueberry and salalberry, traditionally used local berries. They contain very high amounts of tannins, which have beneficial effects in the diet and can prevent chronic disease.


Research group

David (Dawei) Ma (Post-Doc), Harley Gordon (PhD), Eerik Piirtola (PhD), Yalin Liu (MSc), Ahalya Rajendran (PhD), Dr Lynn Yip (Research Associate), Eve Kenny (Undergrad), Megan Loland (Undergrad), Simon Petley (Undergrad)



YearJournal titleTitleAuthors
2023Plant & Cell PhysiologyCRISPR/Cas9 Disruption of MYB134 and MYB115 in Transgenic Poplar Leads to Differential Reduction of Proanthocyanidin Synthesis in Roots and LeavesLiu Yalin, Ma Dawei, Constabel C Peter
2021Plant, Cell & EnvironmentCondensed tannins as antioxidants that protect poplar against oxidative stress from drought and UV‐BGourlay G., Hawkins B.J., Albert A., Schnitzler J-P., Constabel C.P
2022Journal of FungiFungal Community Composition as Affected by Litter Chemistry and Weather during Four Years of Litter Decomposition in Rainshadow Coastal Douglas-Fir ForestsShay P-E, Winder R.S., Constabel C.P., Trofymow J.A
2022The Plant CellCRISPR/Cas9 disruption of UGT71L1 in poplar connects salicinoid and salicylic acid metabolism and alters growth and morphologyGordon H., Fellenberg C., Lackus N.D., Archinuk F., Sproule A., Nakamura Y., Köllner T.G., Gershenzon J., Overy D.P., and Constabel C.P.
2021Journal of Experimental BotanyPoplar MYB117 promotes anthocyanin synthesis and enhances flavonoid B-ring hydroxylation by upregulating the flavonoid 3’,5’-hydroxylase geneDawei Ma, Hao Tang, Michael Reichelt, Eerik-Mikael Piirtola, Juha-Pekka Salminen, Jonathan Gershenzon, and C. Peter Constabel
2021Journal of Chemical EcologyFactors Affecting Foliar Oregonin and Condensed Tannin in Red Alder (Alnus rubra Bong.): Phytochemicals Implicated In Defense Against Western Tent Caterpillar (Malacosoma californicum Packard)Boateng, K., Hawkins, B.J., Yanchuk, A. Fellenberg, C., Constabel, C.P.
2021Journal of Chemical EcologyAnti-herbivore activity of oregonin, a diarylheptanoid found in leaves and bark of red alder (Alnus rubra)Lea C., Bradbury S., and Constabel C.P.
2020Efficient purification of the diarylheptanoid oregonin from red alder (Alnus rubra) leaves and bark combining aqueous extraction, spray drying and flash-chromatographyLea C., Simhadrib C., Bradbury S., Wulff J., and Constabel C.P.
2020SustainabilityNovel integration of geopolymer pavers, silva cells and poplar trees for in-situ treatment of car-wash wastewaterGupta R., Sharma N.R., Valeo C., Garg M., Sharma A., Aneja S., Prasher S.O., and Constabel C.P.
2020Canadian Journal of Forest ResearchRed alder defense mechanisms against western tent caterpillar defoliationBoateng K, Hawkins BJ, Constabel CP, Yanchuk AD, Fellenberg C
2020The Plant JournalDiscovery of salicyl benzoate UDP-glycosyltransferase, a central enzyme in poplar salicinoid phenolic glycoside biosynthesisFellenberg C, Corea O, Lok-Hang Y, Archinuk F, Piirtola E-M, Gordon H, Reichelt M, Brandt W, Wulff J, Ehlting J, Constabel CP
2019Trends in Plant ScienceMYB Repressors as regulators of phenylpropanoid metabolism in plants. Ma D, Constabel CP
2019Tree PhysiologyCondensed tannins are inducible antioxidants and protect hybrid poplar against oxidative stressGourlay G, Constabel CP
2014Molecular EcologyAssociation genetics, geography, and ecophysiology link stomatal patterning in Populus trichocarpa with carbon gain and disease resistance trade-offsMcKown AD, Guy RD, Quamme L, Klápště J, La Mantia J, Constabel CP, El-Kassaby YA, Hamelin RC, Zifkin M, and Azam MS
2018The Plant JournalTwo R2R3-MYB Proteins are broad repressors of flavonoid and phenylpropanoid metabolism in poplarMa D, Reichelt M, Yoshida K, Gershenzon J, Constabel CP
2015Journal of Chemical EcologyInfluence of genotype, environment, and gypsy moth herbivory on local and systemic chemical defenses in trembling aspen (Populus tremuloides)Rubert-Nason KF, Couture JJ, Major IT, Constabel CP and Lindroth
2018Journal of Agricultural and Food ChemistryMolecular controls of proanthocyanidin synthesis and Structure: Prospects for Genetic Engineering in Crop PlantsConstabel, C.P
2017Plant PhysiologyPoplar MYB115 and MYB134 transcription factors regulate proanthocyanidin synthesis and structureJames AM, Ma D, Mellway R, Gesell A, Yoshida K, Walker V, Tran L, Stewart D, Reichelt M, Jussi Suvanto, Salminen J-P, Gershenzon J, Séguin A, and Constabel CP
2017Plant MethodsAn improved butanol-HCl assay for quantification of water-soluble,acetone:methanol-soluble, and insoluble proanthocyanidins (condensed tannins)Shay PE, Trofymow TA, Constabel CP
2016Plant PhysiologyFlavan-3-ols are Effective Chemical Defenses in Poplar against Rust (Melampsora spp.) infection.Ullah C, Unsicker SB, Fellenberg C, Constabel CP, Schmidt A,Gershenzon J, Hammerbacher A
2015PhytochemistryFunctional characterization of two acyltransferases from Populus tri0chocarpa capable of synthesizing benzyl benzoate and salicyl benzoateChedgy RJ, Köllner TG, and Constabel CP
2015Plant PhysiologyThe MYB182 protein downregulates proanthocyanidin and anthocyanin biosynthesis in poplar by repressing both structural and regulatory flavonoid genesYoshida K, Ma D, Constabel CP
2013Frontiers in MicrobiologyThe effects of high-tannin leaf litter from transgenic poplars on microbial communities in microcosm soils. Richard S. Winder, Josyanne Lamarche, C. Peter Constabel, and Richard C. Hamelin
2013PhytochemistryMolecular cloning and biochemical characterization of two UDP-glycosyltransferases from poplar.Veljanovski V and Constabel CP
2012Plant PhysiologyGene expression and metabolite profiling of developing highbush blueberry (Vaccinium corymbosum L.) fruit indicates transcriptional regulation of flavonoid metabolism. Zifkin M, Jin A, Ozga JA, Zaharia I, Schernthaner JP, Gesell A, Abrams S, Kennedy JA and Constabel CP
2012BMC GenomicsThe polyphenol oxidase gene family in land plants: Lineage-specific duplication and expansion.Tran Lan T, Taylor John S, Constabel C Peter
2012Archives of insect biochemistry and physiologyLimited effect of reactive oxygen species on the composition of susceptible essential amino acids in the midguts of Lymantria dispar caterpillars.Barbehenn RV, Niewiadomski J, Kochmanski J and Constabel CP
2012Journal of Chemical EcologyEffects of overproduction of condensed tannins and elevated temperature on chemical and ecological traits of genetically modified hybrid aspens (Populus tremula × P. tremuloides).Kosonen M, Keski-Saari S, Ruuhola T, Constabel CP, Julkunen-
2018BiogeochemistryEvidence for the role and fate of water-insoluble condensed tannins in the short-term reduction of carbon loss during litter decay.Shay PE, Constabel CP, Trofymow TA
2018PhytochemistryPhytochemical analysis of salal berry (Gaultheria shallon Pursh.), a traditionally-consumed fruit from western North America with exceptionally high proanthocyanidin content.Ferguson A, Carvalho E, Gourlay G, Walker V, Martens S, Salminen J-P, Constabel CP
2014Journal of Chemical EcologyTransgenic upregulation of the condensed tannin pathway in poplar leads to a dramatic shift in leaf palatability for two tree-feeding Lepidoptera. Boeckler G. Andreas, Towns Megan, Unsicker Sybille B, Mellway Robin D, Yip Lynn, Hilke Ines, Gershenzon Jonathan, and Constabel CP