Research article - Peer-reviewed, 2002
Independent activation of cold acclimation by low temperature and short photoperiod in hybrid aspen
Welling, Annikki; Moritz, Thomas; Palva, E. Tapio; Junttila, OlaviAbstract
Temperate zone woody plants cold acclimate in response to both short daylength (SD) and low temperature (LT). We were able to show that these two environmental cues induce cold acclimation independently by comparing the wild type (WT) and the transgenic hybrid aspen (Populus tremula X Populus tremuloides Michx.) line 22 overexpressing the oat (Avena saliva) PHYTOCHROME A gene. Line 22 was not able to detect the SD and, consequently, did not stop growing in SD conditions. This resulted in an impaired freezing tolerance development under SD. In contrast, exposure to LT resulted in cold acclimation of line 22 to a degree comparable with the WT. In contrast to the WT, line 22 could not dehydrate the overwintering tissues or induce the production of dehydrins (DHN) under SD conditions. Furthermore, abscisic acid (ABA) content of the buds of line 22 were the same under SD and long daylength, whereas prolonged SD exposure decreased the ABA level in the WT. LT exposure resulted in a rapid accumulation of DHN in both the WT and line 22. Similarly, ABA content increased transiently in both the WT and line 22. Our results indicate that phytochrome A is involved in photoperiodic regulation of ABA and DHN levels, but at LT they are regulated by a different mechanism. Although SD and LT induce cold acclimation independently, ABA and DHN may play important roles in both modes of acclimation.Published in
Plant Physiology2002, volume: 129, number: 4, pages: 1633-1641
Publisher: AMER SOC PLANT BIOLOGISTS
Authors' information
Welling, Annikki
University of Helsinki
Swedish University of Agricultural Sciences, Department of Forest Genetics and Plant Physiology
Palva, E. Tapio
University of Helsinki
Junttila, Olavi
University of Tromso, the Arctic University of Norway (UiT)
UKÄ Subject classification
Botany
Publication Identifiers
DOI: https://doi.org/10.1104/pp.003814
URI (permanent link to this page)
https://res.slu.se/id/publ/42927