Planta

, Volume 216, Issue 2, pp 302–308 | Cite as

Auxin efflux carrier activity and auxin accumulation regulate cell division and polarity in tobacco cells

  • Jan Petrášek
  • Miroslav Elčkner
  • David A. Morris
  • Eva Zažímalová
Original Article

Abstract.

Division and growth of most types of in vitro-cultured plant cells require an external source of auxin. In such cultures, the ratio of external to internal auxin concentration is crucial for the regulation of the phases of the standard growth cycle. In this report the internal concentration of auxin in suspension-cultured cells of Nicotiana tabacum L., strain VBI-0, was manipulated either (i) by increasing 10-fold the normal concentration of 1-naphthaleneacetic acid (NAA) and 2,4-dichlorophenoxyacetic acid in the external medium; or (ii) by addition 1-N-naphthylphthalamic acid (NPA; an inhibitor of auxin efflux and of auxin efflux carrier traffic). Both treatments delayed the onset of cell division for 6–7 days without loss of cell viability. In both cases, cell division activity subsequently resumed coincident with a reduction in the ability of cells to accumulate [3H]NAA from an external medium. Following renewed cell division, a significant proportion of the NPA-treated cells but not those grown at high auxin concentration, exhibited changes in the orientation of new cell divisions and loss of polarity. We conclude that cell division, but not cell elongation, is prevented when the internal auxin concentration rises above a critical threshold value and that the directed traffic of auxin efflux carriers to the plasma membrane may regulate the orientation of cell divisions.

Auxin carrier 1-N-Naphthylphthalamic acid Nicotiana (cell culture) Phytotropin Polar auxin transport 

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Copyright information

© Springer-Verlag 2002

Authors and Affiliations

  • Jan Petrášek
    • 1
  • Miroslav Elčkner
    • 1
  • David A. Morris
    • 1
  • Eva Zažímalová
    • 1
  1. 1.Institute of Experimental Botany, Rozvojová 135, 16502 Prague 6 – Lysolaje, Czech Republic

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