Plant and Soil

, Volume 185, Issue 1, pp 1–12

Regulation of shoot/root ratio by cytokinins from roots inUrtica dioica: Opinion

  • Erwin H. Beck
Opinion Articles

DOI: 10.1007/BF02257560

Cite this article as:
Beck, E.H. Plant Soil (1996) 185: 1. doi:10.1007/BF02257560


According to current knowledge, cytokinins are predominantly root-born phytohormones which are transported into the shoot by the transpiration stream. In the “hormone message concept” they are considered the root signals, which mediate the flux of the photosynthates to the various sinks of the plant. In this review, experiments are assessed, in which changes of the shoot to root ratio of biomass, caused by different levels of nitrogen supply to a model plant,Urtica dioica, could be traced to the natural cytokinin relations of the plant. Disturbance of the internal cytokinin balance of the plant resulted in a disproportionate distribution of the assimilates in favour of the cytokinin-enriched shoot. Inspite of some shortcomings of the “hormone message concept”, the presented work corroborates the significance of root-sourced cytokinins in the regulation of biomass partitioning between shoot and root.

Key words

cytokinins nitrogen supply quantitative patterns and fluxes root signal shoot to root ratio of biomass Urtica dioica 


S/R ratio

shoot:root ratio of biomass (dry matter)




zeatin riboside



Copyright information

© Kluwer Academic Publishers 1996

Authors and Affiliations

  • Erwin H. Beck
    • 1
  1. 1.Lehrstuhl für PflanzenphysiologieUniversität BayreuthBayreuthGermany

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