title: Sulfate determines the glucosinolate concentration of horseradish in vitro plants (Armoracia rusticana Gaertn., Mey. & Scherb.).
abstract: BACKGROUND
  Horseradish plants (Armoracia rusticana) contain high concentrations of glucosinolates. Former studies have revealed that Armoracia plants cultivated in vitro have markedly lower glucosinolate concentrations than those grown in soils. Yet, these studies neglected that the sulfate concentration in the growth medium may have had a strong impact on glucosinolate metabolism. Accordingly, in this study horseradish in vitro plants were cultivated with differing sulfate concentrations and the glucosinolate concentrations were quantified by ion pair HPLC.
  
  
  RESULTS
  Cultivation in 1.7 mmol L(-1) sulfate (as used in the prior studies) resulted in the accumulation of 16.2 µmol g(-1) DW glucosinolates, while the glucosinolate concentration increased to more than 23 µmol g(-1) DW when 23.5 mmol L(-1) sulfate was used in the medium. Correspondingly, the glucosinolate concentration decreased to 1.6 µmol g(-1) DW when sulfate concentration was lowered to 0.2 mmol L(-1).
  
  
  CONCLUSIONS
  Since the glucosinolate accumulation in relation to the sulfate concentration follows a typical saturation curve, we deduce that the availability of sulfate determines the glucosinolate concentration in horseradish in vitro plants.
authors.affiliation: Institute for Plant Biology, Technische Universität Braunschweig, 38106 Braunschweig, Germany.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Alnsour
authors.forename: Maik
authors.initials: M
authors.lastname: Kleinwächter
authors.forename: Julia
authors.initials: J
authors.lastname: Böhme
authors.forename: Dirk
authors.initials: D
authors.lastname: Selmar
mesh_terms: D031215:Armoracia / Q000378:metabolism*; D004032:Diet; D005961:Glucosinolates / Q000378:metabolism*; D006801:Humans; D012987:Soil / Q000737:chemistry*; D013431:Sulfates / Q000378:metabolism*
chemical_list: D005961:Glucosinolates; D012987:Soil; D013431:Sulfates