Concentrations of oxygen and indole-3-acetic acid in the cambial region during latewood formation and dormancy development in Picea abies stems

• Published in: Journal of experimental botany 1998-02, Vol.49 (319), p.205-211
• Main Authors: Eklund, Leif, Little, C.H. Anthony, Riding, Richard T.
• Format: Article
• Language: English
• Subjects: Cambium; dormancy; IAA; indole-3-acetic acid; oxygen; Picea abies; tracheid
• ISSN: 0022-0957; 1460-2431
• DOI: 10.1093/jxb/49.319.205

To manipulate the occurrence of latewood formation and cambial dormancy in Picea abies (L.) Karst. stems, potted seedlings were transferred from the natural environment on 9 July, when tracheids early in the transition between earlywood and latewood were being produced, and cultured for up to 5 weeks in a controlled environment chamber having: (1) Warm LD, (25/15 °C during day/night) and long (16 h) photoperiod, (2) Warm SD, (25/15 °C) and short (8 h) photoperiod, or (3) Cold SD, (18/8 °C) and short (8 h)photoperiod. In Warm LD trees, the radial enlargement of primary-walled derivatives on the xylem side of the cambium, as well as xylem production, continued at the same magnitude throughout the experiment. In Warm SD and Cold SD trees, the radial enlargement of primary-walled derivatives declined and the cambium entered dormancy, both developments occurring faster in the Warm SD trees. The concentration of indole-3-acetic acid (IAA) was higher in developing xylem tissue than in cambium+phloem tissues, but did not vary with environmental treatment or decrease during the experimental period. The O2 concentration in the cambial region followed the order of Cold SD>Warm SD>Warm LD trees and was