Plant and Soil

, Volume 186, Issue 2, pp 361–369

Effects of varied soil nitrogen supply on Norway spruce (Picea abies [L.] Karst.)

II. Carbon metabolism in needles and mycorrhizal roots
  • Thomas Wallenda
  • Christoph Schaeffer
  • Werner Einig
  • Astrid Wingler
  • Rüdiger Hampp
  • Bettina Seith
  • Eckhard George
  • Horst Marschner
Article

DOI: 10.1007/BF02415531

Cite this article as:
Wallenda, T., Schaeffer, C., Einig, W. et al. Plant Soil (1996) 186: 361. doi:10.1007/BF02415531

Abstract

The response of carbohydrate metabolism in 3-year-old Norway spruce plants to an increased amount of nitrogen supply to a N-poor forest soil was investigated in a pot experiment. After 7 months of treatment we found a decreased amount of starch in both needles and roots, together with decreased amounts of sucrose in needles of those plants grown under an enhanced inorganic N supply. In addition, the activity and the protein amount of the anaplerotic enzyme phosphoenolpyruvate carboxylase (PEPC) and the activity of NADP-dependent isocitrate dehydrogenase (IDH) were clearly increased. The activity of sucrose phosphate synthase (SPS) and the pool size of fructose 2,6-bisphosphate (F26BP) were not affected by high supply of inorganic N. These data indicate a shift of carbon flow from starch formation towards an enhanced provision of carbon skeletons for N assimilation and shoot growth. In parallel, we found decreased contents of fungus-specific compounds (ergosterol, mannitol, trehalose) in roots, which are indicators of a decreased colonization by ectomycorrhizal fungi, probably as a result of a changed allocation and partitioning of photoassimilates due to an increased N supply.

Key words

ectomycorrhizafungus-specific compoundsisocitrate dehydrogenasenitrogenPicea abiesphosphoenolpyruvate carboxylase

Abbreviations

DW

dry weight

F26BP

fructose 2,6-bisphosphate

IDH

NADP-dependent isocitrate dehydrogenase

PEPC

phosphoenolpyruvate carboxylase, SPS-sucrose phosphate synthase

Copyright information

© Kluwer Academic Publishers 1996

Authors and Affiliations

  • Thomas Wallenda
    • 1
  • Christoph Schaeffer
    • 1
  • Werner Einig
    • 1
  • Astrid Wingler
    • 1
  • Rüdiger Hampp
    • 1
  • Bettina Seith
    • 2
  • Eckhard George
    • 2
  • Horst Marschner
    • 2
  1. 1.Physiologische Ökologie der Pflanzen, Botanisches InstitutUniversität TübingenTübingenGermany
  2. 2.Institut für PflanzenernährungUniversität HohenheimStuttgartGermany