title: Polyphenols in strawberry (Fragaria × ananassa) leaves induced by plant activators.
abstract: Strawberry leaves contain high amounts of diverse phenolic compounds potentially possessing defensive activities against microbial pathogens and beneficial properties for human health. In this work, young strawberry plants were treated with two plant activators, S-methylbenzo-1,2,3-thaidiazole-7-carbothiate (BTH) and birch wood distillate. Phenolic compounds from activator-treated and control leaves were subjected to quantitative analyses by HPLC-DAD, HPLC-ESI-MS, and microQTOF ESI-MS. Thirty-two different phenolic compounds were detected and characterized, and 21 different ellagitannins constituted the largest group of compounds in the strawberry leaves (37.88-45.82 mg/g dry weight, 47.0-54.3% of total phenolics). Treatment with BTH resulted in higher levels of individual ellagitannins, whereas treatment with birch wood distillate strongly increased the levels of chlorogenic acid in strawberry leaves compared with the control. The results suggest that different plant activators may be useful tools for the activation of different branches in the phenylpropanoid biosynthesis in strawberry.
authors.affiliation: Department of Biology, University of Eastern Finland , P.O. Box 1627, FI-70211 Kuopio, Finland.
authors.forename: Anna
authors.initials: A
authors.lastname: Kårlund
authors.forename: Juha-Pekka
authors.initials: JP
authors.lastname: Salminen
authors.forename: Piia
authors.initials: P
authors.lastname: Koskinen
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Ahern
authors.forename: Maarit
authors.initials: M
authors.lastname: Karonen
authors.forename: Kari
authors.initials: K
authors.lastname: Tiilikkala
authors.forename: Reijo O
authors.initials: RO
authors.lastname: Karjalainen
mesh_terms: D016573:Agrochemicals / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D031985:Fragaria / Q000737:chemistry* / Q000187:drug effects* / Q000378:metabolism; D018515:Plant Leaves / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism; D059808:Polyphenols / Q000032:analysis* / Q000096:biosynthesis
chemical_list: D016573:Agrochemicals; D059808:Polyphenols