Abstract

The simultaneous uptake of 13 different amino acids by Scots pine (Pinus sylvestris L.) was characterized and its regulation investigated after pre-treatments with a range of C and N metabolites. The uptake system exhibited a broad substrate specificity, acquiring all tested amino acids at similar uptake rates. Uptake of all tested amino acids by excised roots was linear over a time period of 150 min and exhibited pH-dependency, showing a peak at pH 4.0-5.0. Uptake was increased following pre-treatments with glucose and sucrose, while ammonium pre-treatments had a negative effect on amino acid acquisition. Pre-treatments with the important Krebs cycle intermediates oxaloacetate or 2-oxoglutarate did not result in altered amino acid uptake. It is speculated that the up-regulation of uptake may be due to an increased flow of glucose through a sensor mechanism, such as hexokinase. The regulation of transport by N and C suggests a function for amino acid uptake in the N nutrition of the plant, thus further highlighting the importance of organic nitrogen for plant N nutrition suggested by an increasing amount of research

Keywords

Amino acid uptake; regulation (amino acid uptake) Pinus; nitrogen nutrition; nitrogen uptake

Published in

Planta
2003, Volume: 217, number: 2, pages: 309-315
Publisher: SPRINGER-VERLAG

SLU Authors

• Näsholm, Torgny

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

• Persson, Jörgen

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Forest Science


Publication identifier

DOI: https://doi.org/10.1007/s00425-003-0991-x

Permanent link to this page (URI)

https://res.slu.se/id/publ/1119