Investigation on the Assimilation of Nitrogen by Maize Roots and the Transport of Some Major Nitrogen Compounds by Xylem Sap

I. Nitrate and Ammonia Uptake and Assimilation in the Major Nitrogen Fractions of Nitrogen-starved Maize Roots

Authors

  • S. IVANKO,

    1. Department of Radiobiology and Biochemistry, University of Agriculture, Nitra, Czechoslovakia and Agricultural Research Department, Danish Atomic Energy Commission, Research Establishment Risö, DK-4000 Roskilde, Denmark
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  • J. INGVERSEN

    1. Department of Radiobiology and Biochemistry, University of Agriculture, Nitra, Czechoslovakia and Agricultural Research Department, Danish Atomic Energy Commission, Research Establishment Risö, DK-4000 Roskilde, Denmark
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Abstract

The uptake and assimilation of nitrate and ammonia have been studied in Zea mays. Nitrogen-starved maize roots are capable of accumulating a potential capacity for nitrogen uptake and assimilation. Reestablishment of nitrogen supply leads to intense uptake, reaching 154 % of the reference variant level after 24 hours when nitrate is supplied, and 121 % when ammonia is supplied. After 24 hours the insoluble nitrogen fraction accounts for 80, 54 and 55 % of the total taken up in the PK + NO3-, PK + NH4+ and NPK variants respectively.

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