Phytogeographic and genetic variation in Sorbus, a traditional antidiabetic medicine-adaptation in action in both a plant and a discipline

Anna Bailie; Sebastien Renaut; Eliane Ubalijoro; José A Guerrero-Analco; Ammar Saleem; Pierre Haddad; John T Arnason; Timothy Johns; Alain Cuerrier

doi:10.7717/peerj.2645

Phytogeographic and genetic variation in Sorbus, a traditional antidiabetic medicine-adaptation in action in both a plant and a discipline

PeerJ. 2016 Nov 3:4:e2645. doi: 10.7717/peerj.2645. eCollection 2016.

Authors

Anna Bailie¹, Sebastien Renaut², Eliane Ubalijoro³, José A Guerrero-Analco⁴, Ammar Saleem⁵, Pierre Haddad⁶, John T Arnason⁵, Timothy Johns⁷, Alain Cuerrier⁸

Affiliations

¹ Department of Plant Science, McGill University, Ste-Anne-de-Bellevue, QC, Canada; Jardin Botanique de Montréal, Institut de Recherche en Biologie Végétale, Montreal, QC, Canada.
² Département de Sciences Biologiques, Institut de Recherche en Biologie Végétale, Université de Montréal , Montreal , QC , Canada.
³ Institute for the Study of International Development, McGill University , Montreal , QC , Canada.
⁴ Department of Biology, University of Ottawa, Ottawa, ON, Canada; Red de Estudios Moleculares Avanzados, Instituto de Ecología A.C, Xalapa, Veracruz, Mexico.
⁵ Department of Biology, University of Ottawa , Ottawa , ON , Canada.
⁶ Département de Pharmacologie, University of Montreal , Montreal , QC , Canada.
⁷ Department of Plant Science, McGill University, Ste-Anne-de-Bellevue, QC, Canada; School of Dietetics and Human Nutrition, McGill University, Ste-Anne-de-Bellevue, QC, Canada.
⁸ Jardin Botanique de Montréal, Institut de Recherche en Biologie Végétale , Montreal , QC , Canada.

Abstract

Mountain ash (Sorbus decora and S. americana) is used by the Cree Nation of the James Bay region of Quebec (Eeyou Istchee) as traditional medicine. Its potential as an antidiabetic medicine is thought to vary across its geographical range, yet little is known about the factors that affect its antioxidant capacity. Here, we examined metabolite gene expression in relation to antioxidant activity, linking phytochemistry and medicinal potential. Samples of leaf and bark from S. decora and S. americana were collected from 20 populations at four different latitudes. Two genes known to produce antidiabetic substances, flavonol synthase and squalene synthase, were analyzed using quantitative real time PCR. Gene expression was significantly higher for flavonol synthase compared to squalene synthase and increased in the most Northern latitude. Corresponding differences observed in the antioxidant capacity of ethanolic extracts from the bark of Sorbus spp. confirm that plants at higher latitudes increase production of stress-induced secondary metabolites and support Aboriginal perceptions of their higher medicinal potential. Modern genetic techniques such as quantitative real time PCR offer unprecedented resolution to substantiate and scrutinise Aboriginal medicinal plant perception. Furthermore, it offers valuable insights into how environmental stress can trigger an adaptive response resulting in the accumulation of secondary metabolites with human medicinal properties.

Keywords: Adaptation; Antioxidant; Ethnobotany; Phytochemistry; Quantitative rtPCR; Sorbus.

Grants and funding

This work is supported by a Canadian Institute for Health Research grant awarded to TAAM (Haddad, Cuerrier, Johns), the Natural Sciences and Engineering Research Council (NSERC) (Discovery Grant to T Johns) and funds awarded to A Bailie from McGill University. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.