title: [Effect of nitrogen, phosphorus and potassium deficiency on content of phenolic compounds in exudation of American ginseng].
abstract: OBJECTIVE
  Some of the phenolic compounds detected in the soil of commercially cultivated American ginseng could inhibit the seed germination and seedling growth of American ginseng. In this paper we studied the root exudation of American ginseng induced by deficiency of nitrogen, phosphorus and potassium on the content of phenolic compounds.
  
  
  METHODS
  Two years old American ginsengs were cultured in hydroponic culture with different nutrient solution. The culture solution was collected after 14 days. The exudations of different polarities in the culture solution were enriched by the amberlite XAD4 and XAD7. The content of the total phenolic acids in the exudation was analyzed by Folin-Ciocalteu colorimetry; the contents of vanillic acid, p-coumaric acid and trans-cinnamic acid were detected and quantified by HPLC.
  
  
  RESULTS
  Both in the situation of nitrogen and potassium deficiency, the concentration of total phenolic compounds increased significantly in the exudation of American ginseng comparing with the complete nutrient solution (P < 0.05) , while decreased significantly under phosphorus deficient conditions (P < 0.05). The contents of the 3 autotoxic phenolic acids decreased significantly under nitrogen, phosphorus and potassium deficient conditions (P < 0.05).
  
  
  CONCLUSIONS
  The contents of total phenolic compounds and the 3 autotoxic phenolics in the root exudation of American ginseng altered variously in the deficiency of nitrogen, phosphorus and potassium.
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193, China.
authors.lastname: Du Jing
authors.forename: Jiaxue
authors.initials: J
authors.lastname: Yang
authors.forename: Xiaolin
authors.initials: X
authors.lastname: Jiao
authors.forename: Weiwei
authors.initials: W
authors.lastname: Gao
mesh_terms: D003373:Coumaric Acids / Q000032:analysis; D062385:Hydroxybenzoates / Q000032:analysis*; D009584:Nitrogen / Q000172:deficiency; D005894:Panax / Q000737:chemistry* / Q000378:metabolism; D010758:Phosphorus / Q000172:deficiency; D053147:Plant Exudates / Q000737:chemistry*; D018517:Plant Roots / Q000737:chemistry / Q000378:metabolism; D011188:Potassium / Q000737:chemistry; D011422:Propionates; D012987:Soil / Q000737:chemistry; D014641:Vanillic Acid / Q000032:analysis
chemical_list: D003373:Coumaric Acids; D062385:Hydroxybenzoates; D053147:Plant Exudates; D011422:Propionates; D012987:Soil; D010758:Phosphorus; D014641:Vanillic Acid; C017616:phenolic acid; C495469:p-coumaric acid; D009584:Nitrogen; D011188:Potassium