title: Salicylic acid and salicylic acid glucoside in xylem sap of Brassica napus infected with Verticillium longisporum.
abstract: Salicylic acid (SA) and its glucoside (SAG) were detected in xylem sap of Brassica napus by HPLC-MS. Concentrations of SA and SAG in xylem sap from the root and hypocotyl of the plant, and in extracts of shoots above the hypocotyl, increased after infection with the vascular pathogen Verticillium longisporum. Both concentrations were correlated with disease severity assessed as the reduction in shoot length. Furthermore, SAG levels in shoot extracts were correlated with the amount of V. longisporum DNA in the hypocotyls. Although the concentration of SAG (but not SA) in xylem sap of infected plants gradually declined from 14 to 35 days post infection, SAG levels remained significantly higher than in uninfected plants during the whole experiment. Jasmonic acid (JA) and abscisic acid (ABA) levels in xylem sap were not affected by infection with V. longisporum. SA and SAG extend the list of phytohormones potentially transported from root to shoot with the transpiration stream. The physiological relevance of this transport and its contribution to the distribution of SA in plants remain to be elucidated.
authors.affiliation: Molecular Phytopathology and Mycotoxin Research Unit, Department of Crop Sciences, Goettingen University, 37077 Göttingen, Germany.
authors.forename: Astrid
authors.initials: A
authors.lastname: Ratzinger
authors.forename: Nadine
authors.initials: N
authors.lastname: Riediger
authors.forename: Andreas
authors.initials: A
authors.lastname: von Tiedemann
authors.forename: Petr
authors.initials: P
authors.lastname: Karlovsky
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D018533:Biomass; D029688:Brassica napus / Q000378:metabolism* / Q000382:microbiology*; D002851:Chromatography, High Pressure Liquid; D003517:Cyclopentanes / Q000378:metabolism; D004271:DNA, Fungal / Q000378:metabolism; D005960:Glucosides / Q000378:metabolism*; D013058:Mass Spectrometry; D054883:Oxylipins / Q000378:metabolism; D010935:Plant Diseases / Q000382:microbiology; D010936:Plant Extracts / Q000378:metabolism; D053147:Plant Exudates / Q000378:metabolism*; D018520:Plant Shoots / Q000378:metabolism / Q000382:microbiology; D012459:Salicylates / Q000378:metabolism*; D020172:Verticillium / Q000502:physiology*; D052584:Xylem / Q000378:metabolism* / Q000382:microbiology*
chemical_list: D003517:Cyclopentanes; D004271:DNA, Fungal; D005960:Glucosides; D054883:Oxylipins; D010936:Plant Extracts; D053147:Plant Exudates; D012459:Salicylates; C084746:salicylic acid glucoside; C011006:jasmonic acid; D000040:Abscisic Acid