Trees

, Volume 3, Issue 3, pp 125–137

Participation of auxin and abscisic acid in the regulation of seasonal variations in cambial activity and xylogenesis

Authors

  • Suzanne Lachaud
    • Laboratoire de Biologie et Physiologie Végétale (URA 81), Station Biologique de Beau-SiteUniversité de Poitiers
Review Article

DOI: 10.1007/BF00226647

Cite this article as:
Lachaud, S. Trees (1989) 3: 125. doi:10.1007/BF00226647

Summary

The current notion that hormonal level and cell response are clearly correlated has often been challenged recently. During the period of cambial activity, auxin content seems to control the intensity of mitosis and some features of the resulting wood, but not the duration of the active period itself. During cambial rest, the indole-3-acetic acid (IAA) level often remains high in the cambium, but the cell sensitivity to auxin is low. The decrease of auxin transport in autumn is sometimes interpreted as a major qualitative change affecting the pattern of transport, and sometimes as a secondary change occurring later than rest onset. The causes of the seasonal variation of cambial response remain unknown. A hypothesis is proposed that accounts for the structural-functional changes occurring in cambial cells during the onset of dormancy. Abscisic acid (ABA) may reduce wood production and xylem cell enlargement in late summer. An important amount of ABA may be present in the cambial zone in autumn after drought stress and in spring in the young growing shoot. Changes in ABA level do not appear to be clearly correlated with the different steps of cambial rest and activity. Beyond the role of ABA as a stress mediator, its participation in the annual regulation of cambial activity remains unclear. Its distribution in the most alkaline compartments may account for the particularities of its seasonal activity. The involvement of IAA and ABA in cambial growth is discussed within the scope of a possible annual alternation of two different metabolisms in the cambial cell.

Key words

Cambial activityAuxinAbscisic acidDormancyTransport

Abbreviations

ABA

abscisic acid

DPA

dihydrophaseic acid

GA

gibberellic acid

GC-MS

gas chromatography-mass spectrometry

IAA

indole-3-acetic acid

PA

phaseic acid

RNA

ribonucleic acid

SICM

single ion current monitoring

SIM

selected ion monitoring

Copyright information

© Springer-Verlag 1989