Level of endogenous indole-3-acetic acid in the stem of Pinus sylvestris in relation to the seasonal variation of cambial activity
Article first published online: 28 APR 2006
Plant, Cell & Environment
Volume 14, Issue 2, pages 241–246, March 1991
How to Cite
SUNDBERG, B., LITTLE, C. H. A., CUI, K. and SANDBERG, G. (1991), Level of endogenous indole-3-acetic acid in the stem of Pinus sylvestris in relation to the seasonal variation of cambial activity. Plant, Cell & Environment, 14: 241–246. doi: 10.1111/j.1365-3040.1991.tb01342.x
- Issue published online: 28 APR 2006
- Article first published online: 28 APR 2006
- Received 11 June 1990; received in revised form 3 October 1990; accepted for publication 17 October 1990
- cambial activity;
- indolc-3-acetic acid;
- Scots pine (Pinus sylvestris L.).
Abstract. Gas chromatography – selected ion monitoring – mass spectrometry was used to measure the level of indole-3-acetic acid (IAA) in the cambial region at the top and bottom of the branchless portion of the main stem of three large Scots pine trees, at weekly intervals from 28 April to 13 July. During this period, the cambium reactivated from the dormant state and entered its ‘grand’ period of xylem and phloem production, which was monitored by microscopy. The total amount of IAA (ng cm−2) increased steadily from 28 April until late June, and thereafter remained constant. In contrast, the concentration of IAA (ng g−1 fresh weight) was high at the start of cambial reactivation, declined when the number of differentiating tracheids began to increase, and then rose as the number of cells decreased. The timing and magnitude of the changes in xylem and phloem production and in IAA level were similar at the two sampling positions. It is concluded that the seasonal changes in cambial activity in the conifer stem cannot be ascribed simply to a fluctuation in the level of endogenous IAA in the cambial region.