Plant Growth Regulation

, Volume 25, Issue 2, pp 123–126

Cytokinins in the vascular saps of Ricinus communis

  • J.S. Kamboj
  • P.S. Blake
  • D.A. Baker
Article

DOI: 10.1023/A:1006016023707

Cite this article as:
Kamboj, J., Blake, P. & Baker, D. Plant Growth Regulation (1998) 25: 123. doi:10.1023/A:1006016023707

Abstract

Roots are recognised as the major sites of cytokinin synthesis and shoots receive a continuous supply of cytokinins from the roots. Although reports are available on the xylem mobility of putative free bases and their ribosides, relatively few studies on the phloem mobility of cytokinins have been reported. The origin of phloem-mobile cytokinins is uncertain but there is evidence which implicates a recirculation from the root source. This study is the first report in which zeatin and zeatin riboside from the root pressure exudate and phloem sap of Ricinus have been identified by full-scan GC-MS and quantified by GC-MS selective-ion-monitoring. In this study, the concentration of cytokinins in root pressure exudate was similar, but lower, and in the phloem sap higher than that reported previously. The concentration of cytokinins quantified in the phloem sap confirms their transport in the sieve tubes. The relatively high concentration of zeatin riboside detected in the root pressure exudate and of zeatin detected in the phloem sap indicate a possible vascular recirculation of these hormones.

cytokinins vascular sap Ricinus GC-MS zeatin zeatin riboside 

Copyright information

© Kluwer Academic Publishers 1998

Authors and Affiliations

  • J.S. Kamboj
    • 1
  • P.S. Blake
    • 1
  • D.A. Baker
    • 2
  1. 1.East Malling, West MallingHorticulture Research InternationalKentUK
  2. 2.Wye CollegeUniversity of London, AshfordKentUK

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