© 2006 Heron Publishing—Victoria, Canada
Correlating gene expression to physiological parameters and environmental conditions during cold acclimation of Pinus sylvestris, identification of molecular markers using cDNA microarrays
Ronny V. L. Joosen (1, 7), Michiel Lammers (1, 7), Peter A. Balk (2), Peter Brønnum (3), Maurice C. J. M. Konings (1), Mike Perks (4), Eva Stattin (5), Monique F. van Wordragen (2) and A. (Lonneke) H. M. van der Geest (1, 6)
1. Plant Research International B.V., P.O. Box 16, 6700 AA Wageningen, The Netherlands / 2. Agrotechnology and Food Innovations, P.O. Box 17, 6700 AA Wageningen, The Netherlands / 3. Danish Institute of Agricultural Sciences, Kirstinebjergvej 10, DK-5792 Aarslev, Denmark / 4. Forestry Research Northern Research Station, Roslin, Midlothian EH25 9SY, U.K. / 5. Dalarna University, Herrgårdsvägen 122, 776 98 Garpenberg, Sweden / 6. Corresponding author (lonneke.vandergeest@wur.nl) / 7. These authors contributed equally to this work and should be considered first author / Received September 2, 2005; accepted January 17, 2006; published online June 30, 2006
Summary
Scots pine (Pinus sylvestris L.) seedlings were grown under different conditions (three field locations, two seasons and two climate room regimes), and
then analyzed for freezing tolerance of shoots and roots and for transcript abundance in apical buds based on a cDNA microarray
containing about 1500 expressed sequence tags (ESTs) from buds of cold-treated Scots pine seedlings. In a climate room providing
long daily photoperiods and high temperatures, seedlings did not develop freezing tolerance, whereas seedlings in a climate
room set to provide declining temperatures and day lengths developed moderate freezing tolerance. Control seedlings grown
outside under field conditions developed full freezing tolerance. Differences in physiological behavior of the different seedling
groups, combined with molecular analysis, allowed identification of a large group of genes, expression of which changed during
the development of freezing tolerance. Transcript abundance of several of these genes was highly correlated with freezing
tolerance in seedlings differing in provenance, field location or age, making them excellent candidate marker genes for molecular
tests for freezing tolerance.
Keywords:
apical buds, climate room, field, freezing tolerance, gene expression, mRNA level, root electrolyte leakage, Scots pine, seedlings,
shoot electrolyte leakage, transcript abundance.
