title: Comparative phloem chemistry of Manchurian (Fraxinus mandshurica) and two North American ash species (Fraxinus americana and Fraxinus pennsylvanica).
abstract: Recent studies have investigated interspecific variation in resistance of ash (Fraxinus spp.) to the exotic wood-boring beetle, emerald ash borer (EAB, Agrilus planipennis). Manchurian ash (Fraxinus mandshurica) is an Asian species that has coevolved with EAB. It experiences little EAB-induced mortality compared to North American ashes. Host phloem chemistry, both constitutive and induced, might partly explain this interspecific variation in resistance. We analyzed the constitutive phloem chemistry of three ash species: Manchurian ash and North American white (Fraxinus americana) and green (Fraxinus pennsylvanica) ash. Analysis of the crude phloem extracts revealed the presence of an array of phenolic compounds including hydroxycoumarins, a monolignol, lignans, phenylethanoids, and secoiridoids. Both qualitative and quantitative differences were observed among the three ash species. Hydroxycoumarins and the phenylethanoids, calceloariosides A and B, were present only in the phloem of Manchurian ash and might represent a mechanism of resistance against EAB.
authors.affiliation: Department of Plant Pathology, The Ohio State University, 201 Kottman Hall, 2021 Coffey Road, Columbus, OH 43210, USA. eyles.1@osu.edu
authors.forename: Alieta
authors.initials: A
authors.lastname: Eyles
authors.forename: William
authors.initials: W
authors.lastname: Jones
authors.forename: Ken
authors.initials: K
authors.lastname: Riedl
authors.forename: Don
authors.initials: D
authors.lastname: Cipollini
authors.forename: Steven
authors.initials: S
authors.lastname: Schwartz
authors.forename: Kenneth
authors.initials: K
authors.lastname: Chan
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Herms
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Bonello
mesh_terms: D002851:Chromatography, High Pressure Liquid; D031661:Fraxinus / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D052585:Phloem / Q000737:chemistry*; D013045:Species Specificity; D021241:Spectrometry, Mass, Electrospray Ionization; D013056:Spectrophotometry, Ultraviolet