title: Biofortification and bioavailability of rice grain zinc as affected by different forms of foliar zinc fertilization.
abstract: BACKGROUND
  Zinc (Zn) biofortification through foliar Zn application is an attractive strategy to reduce human Zn deficiency. However, little is known about the biofortification efficiency and bioavailability of rice grain from different forms of foliar Zn fertilizers.
  
  
  RESULTS
  Four different Zn forms were applied as a foliar treatment among three rice cultivars under field trial. Zinc bioavailability was assessed by in vitro digestion/Caco-2 cell model. Foliar Zn fertilization was an effective agronomic practice to promote grain Zn concentration and Zn bioavailability among three rice cultivars, especially, in case of Zn-amino acid and ZnSO(4). On average, Zn-amino acid and ZnSO(4) increased Zn concentration in polished rice up to 24.04% and 22.47%, respectively. On average, Zn-amino acid and ZnSO(4) increased Zn bioavailability in polished rice up to 68.37% and 64.43%, respectively. The effectiveness of foliar applied Zn-amino acid and ZnSO(4) were higher than Zn-EDTA and Zn-Citrate on improvement of Zn concentration, and reduction of phytic acid, as a results higher accumulation of bioavailable Zn in polished rice. Moreover, foliar Zn application could maintain grain yield, the protein and minerals (Fe and Ca) quality of the polished rice.
  
  
  CONCLUSIONS
  Foliar application of Zn in rice offers a practical and useful approach to improve bioavailable Zn in polished rice. According to current study, Zn-amino acid and ZnSO(4) are recommended as excellent foliar Zn forms to ongoing agronomic biofortification.
authors.affiliation: Ministry of Education (MOE) Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Hangzhou, People's Republic of China.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Wei
authors.forename: M J I
authors.initials: MJ
authors.lastname: Shohag
authors.forename: Xiaoe
authors.initials: X
authors.lastname: Yang
mesh_terms: D018938:Caco-2 Cells; D002523:Edible Grain / Q000187:drug effects / Q000378:metabolism*; D005308:Fertilizers; D006801:Humans; D012275:Oryza / Q000187:drug effects / Q000378:metabolism*; D010833:Phytic Acid / Q000378:metabolism; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D015032:Zinc / Q000378:metabolism*; D017967:Zinc Compounds / Q000494:pharmacology; D019287:Zinc Sulfate / Q000494:pharmacology
chemical_list: D005308:Fertilizers; D017967:Zinc Compounds; D019287:Zinc Sulfate; D010833:Phytic Acid; D015032:Zinc