Influence of nitrogen and sulfur on biomass production and carotenoid and glucosinolate concentrations in watercress (Nasturtium officinale R. Br.)

J Agric Food Chem. 2007 Dec 26;55(26):10628-34. doi: 10.1021/jf072793f. Epub 2007 Dec 4.

Abstract

Watercress (Nasturtium officinale R. Br.) is a perennial herb rich in the secondary metabolites of glucosinolates and carotenoids. 2-phenethyl isothiocyanate, the predominate isothiocyanate hydrolysis product in watercress, can reduce carcinogen activation through inhibition of phase I enzymes and induction of phase II enzymes. Sulfur (S) and nitrogen (N) have been shown to influence concentrations of both glucosinolates and carotenoids in a variety of vegetable crops. Our research objectives were to determine how several levels of N and S fertility interact to affect watercress plant tissue biomass production, tissue C/N ratios, concentrations of plant pigments, and glucosinolate concentrations. Watercress was grown using nutrient solution culture under a three by three factorial arrangement, with three S (8, 16, and 32 mg/L) and three N (6, 56, and 106 mg/L) fertility concentrations. Watercress shoot tissue biomass, tissue %N, and tissue C/N ratios were influenced by N but were unaffected by changes in S concentrations or by the interaction of NxS. Tissue pigment concentrations of beta-carotene, lutein, 5,6-epoxylutein, neoxanthin, zeaxanthin, and the chlorophyll pigments responded to changes in N treatment concentrations but were unaffected by S concentrations or through N x S interactions. Watercress tissue concentrations of aromatic, indole, and total glucosinolate concentrations responded to changes in N treatments; whereas aliphatic, aromatic, and total glucosinolates responded to changes in S treatment concentrations. Individual glucosinolates of glucobrassicin, 4-methoxyglucobrassicin, and gluconasturriin responded to N fertility treatments, while gluconapin, glucobrassicin, and gluconasturiin responded to changes in S fertility concentrations. Increases in carotenoid and glucosinolate concentrations through fertility management would be expected to influence the nutritional value of watercress in human diets.

MeSH terms

  • Biomass
  • Carotenoids / analysis*
  • Chlorophyll / analysis
  • Glucosinolates / analysis*
  • Nasturtium / chemistry*
  • Nasturtium / drug effects*
  • Nasturtium / growth & development
  • Nitrogen / pharmacology*
  • Sulfur / pharmacology*

Substances

  • Glucosinolates
  • Chlorophyll
  • Carotenoids
  • Sulfur
  • Nitrogen