title: Raman spectroscopic analysis of the effect of the lichenicolous fungusXanthoriicola physciaeon its lichen host.
abstract: Lichenicolous (lichen-dwelling) fungi have been extensively researched taxonomically over many years, and phylogenetically in recent years, but the biology of the relationship between the invading fungus and the lichen host has received limited attention, as has the effects on the chemistry of the host, being difficult to examine in situ.Raman spectroscopy is an established method for the characterization of chemicals in situ, and this technique is applied to a lichenicolous fungus here for the first time.Xanthoriicola physciaeoccurs in the apothecia ofXanthoria parietina, producing conidia at the hymenium surface. Raman spectroscopy of apothecial sections revealed that parietin and carotenoids were destroyed in infected apothecia. Those compounds protect healthy tissues of the lichen from extreme insolation and their removal may contribute to the deterioration of the apothecia. Scytonemin was also detected, but was most probably derived from associated cyanobacteria. This work shows that Raman spectroscopy has potential for investigating changes in the chemistry of a lichen by an invading lichenicolous fungus.
authors.affiliation: Centre for Astrobiology & Extremophiles Research, Division of Chemical &Forensic Sciences, School of Life Sciences, University of Bradford, Bradford, BD7 1DP UK.
authors.forename: Howell G M
authors.initials: HG
authors.lastname: Edwards
authors.affiliation: School of Archaeological Sciences, University of Bradford, Bradford, BD7 1DP UK.
authors.forename: Mark R D
authors.initials: MR
authors.lastname: Seaward
authors.affiliation: 34 Meadowbrook, Twmpath Lane, Gobowen, Oswestry, Shropshire SY10 7HD UK.
authors.forename: Tom F
authors.initials: TF
authors.lastname: Preece
authors.affiliation: Area Geodinamica Interna, Facultad de Humanidades y Educacion, Universidad de Burgos, Calle Villadiego s/n, 09001 Burgos, Spain.
authors.forename: Susana E
authors.initials: SE
authors.lastname: Jorge-Villar
authors.affiliation: Departamento de Biología Vegetal II, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza Ramón y Cajal, 28040 Madrid, Spain ; Department of Life Sciences, The Natural History Museum, Cromwell Road, London, SW7 5BD UK ; Comparative Plant and Fungal Biology, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3DS UK.
authors.forename: David L
authors.initials: DL
authors.lastname: Hawksworth
keywords: Parasitism; Parietin; Pathogenicity; Protective biochemicals; Scytonemin; Xanthoria parietina