title: Ammonium reduces oxalate accumulation in different spinach (Spinacia oleracea L.) genotypes by inhibiting root uptake of nitrate.
abstract: Excessive accumulation of oxalate negatively affects nutritional value of many vegetables, such as spinach (Spinacia oleracea L.). Mixed solution of ammonium and nitrate could effectively reduce oxalate accumulation, while the mechanism involved remains unknown. High (Heizhenzhu) and low (Weilv) oxalate-accumulated spinach genotypes were used in this study to investigate the association of oxalate accumulation and root uptake of nitrogen. Exposure of increasing nitrate or mixed-nitrogen (nitrate:ammonium = 1:1) significantly increased leaf total and soluble oxalate contents. In contrast, increasing ammonium did not result in elevation of leaf oxalate. Correlation analysis confirmed that leaf oxalate accumulation was positively associated with root uptake of nitrate but not ammonium. Moreover, addition of ammonium significantly reduced nitrate uptake rate, and subsequently decreased leaf oxalate accumulation. The results suggest that oxalate synthesis in spinach leaves is associated with its root uptake of nitrate, and ammonium is able to reduce oxalate accumulation by inhibiting uptake of nitrate.
authors.affiliation: MOE Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource & Environmental Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Liu
authors.affiliation: MOE Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource & Environmental Sciences, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Subtropical Soil Science and Plant Nutrition of Zhejiang Province, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Lingli
authors.initials: L
authors.lastname: Lu
authors.affiliation: MOE Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource & Environmental Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Qiuhui
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Agricultural Experiment Station, Zhejiang University, Hangzhou 310058, China.
authors.forename: Wenya
authors.initials: W
authors.lastname: Ding
authors.affiliation: MOE Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource & Environmental Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Peibin
authors.initials: P
authors.lastname: Dai
authors.affiliation: MOE Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource & Environmental Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Hu
authors.affiliation: MOE Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource & Environmental Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Yu
authors.affiliation: MOE Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource & Environmental Sciences, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Subtropical Soil Science and Plant Nutrition of Zhejiang Province, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Chongwei
authors.initials: C
authors.lastname: Jin
authors.affiliation: MOE Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource & Environmental Sciences, Zhejiang University, Hangzhou 310058, China; Agricultural Experiment Station, Zhejiang University, Hangzhou 310058, China. Electronic address: xylin@zju.edu.cn.
authors.forename: Xianyong
authors.initials: X
authors.lastname: Lin
mesh_terms: D064751:Ammonium Compounds / Q000494:pharmacology*; D005838:Genotype; D009566:Nitrates / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D010070:Oxalates / Q000378:metabolism*; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism*; D018724:Spinacia oleracea / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*
chemical_list: D064751:Ammonium Compounds; D009566:Nitrates; D010070:Oxalates; D009584:Nitrogen; C006568:ammonium nitrate
keywords: Ammonium; Genotype; Nitrate; Oxalate (PubChem CID: 971); Oxalate accumulation; Spinach