Addition of Arbuscular Mycorrhizal Fungi Enhances Terpene Synthase Expression in Salvia rosmarinus Cultivars

Emily Leggatt, Alistair Griffiths, Simon Budge, Tony Stead, Alan Gange, Paul Devlin

Research output: Contribution to journalArticlepeer-review


Culinary herbs are commercially cultivated for their wide range of volatile compounds
that give characteristic aromas and tastes. Rosemary (Salvia rosmarinus Spenn.) is an excellent model
for assessment of methods improvement of volatile production as cultivars offer a wide variety of
aromatic profiles due to the large family of terpene synthase genes. Arbuscular mycorrhizal fungi
(AMF) associations have been shown to improve essential oil production in aromatic plants and
offer one approach to enhance aroma in commercial herb production. Changes in the expression of
seven different terpene synthases were compared in six rosemary cultivars in response to addition of
AMF to a peat substrate. Addition of AMF profoundly influenced terpene synthase expression in all
cultivars and did so without impacting the optimised plant size and uniformity achieved in these
conditions. In addition, two methods for AMF application, developed with the horticultural industry
in mind, were tested in this study. Uniform incorporation of AMF mixed into the growing substrate
prior to planting of a root plug produced the most consistent root colonisation. Overall, our findings
demonstrate the potential for the use of AMF in the improvement of aroma in culinary herbs within a
commercial setting but show that outcomes are likely to greatly vary depending on variety.
Original languageEnglish
Issue number315
Publication statusPublished - 23 Jan 2023

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