†Present address: Plant Molecular Biology Lab, Institute of Biotechnology, PO Box 56, FIN-00014 University of Helsinki, Finland.
The MADS-box gene DAL1 is a potential mediator of the juvenile-to-adult transition in Norway spruce (Picea abies)
Article first published online: 23 SEP 2004
The Plant Journal
Volume 40, Issue 4, pages 546–557, November 2004
How to Cite
Carlsbecker, A., Tandre, K., Johanson, U., Englund, M. and Engström, P. (2004), The MADS-box gene DAL1 is a potential mediator of the juvenile-to-adult transition in Norway spruce (Picea abies). The Plant Journal, 40: 546–557. doi: 10.1111/j.1365-313X.2004.02226.x
- Issue published online: 27 SEP 2004
- Article first published online: 23 SEP 2004
- Received 8 April 2004; revised 30 July 2004; accepted 20 August 2004.
- MADS transcription factor;
Progression through the plant life cycle involves change in many essential features, most notably in the capacity to reproduce. The transition from a juvenile vegetative and non-reproductive to an adult reproductive phase is gradual and can take many years; in the conifer Norway spruce, Picea abies, typically 20–25 years. We present a detailed analysis of the activities of three regulatory genes with potential roles in this transition in Norway spruce: DAL1, a MADS-box gene related to the AGL6 group of genes from angiosperms, and the two LEAFY-related genes PaLFY and PaNLY. DAL1 activity is initiated in the shoots of juvenile trees at an age of 3–5 years, and then increases with age, whereas both LFY genes are active throughout the juvenile phase. The activity of DAL1 further shows a spatial pattern along the stem of the tree that parallels a similar gradient in physiological and morphological features associated with maturation to the adult phase. Constitutive expression of DAL1 in transgenic Arabidopsis plants caused a dramatic attenuation of both juvenile and adult growth phases; flowers forming immediately after the embryonic phase of development in severely affected plants. Taken together, our results support the notion that DAL1 may have a regulatory role in the juvenile-to-adult transition in Norway spruce.