The influence of the level of potassium supply to young tobacco plants (Nicotiana tabacum L.) on short‐term uptake and utilisation of nitrate nitrogen (¹⁵N)

The influence of the level of potassium supply on the incorporation of labelled nitrogen ( 15 N) was studied in young tobacco plants. During a 4‐h period the plants, which were well supplied with potassium, absorbed a greater amount of labelled nitrogen and utilisation of this nitrogen for the synthesis of organic nitrogen compounds occurred more rapidly. The results clearly indicate that in the plants with lower K supply soluble amino acids accumulated whereas in the “+K” plants the incorporation of amino nitrogen into the protein fraction was accelerated.