Lodgepole pine
Pinus contorta
One-year-old lodgepole pine seedlings were supplied by the government of British Columbia representing five seed-zones (Central Plateau, Prince George, Thompson Okanagan, Bulkley Valley and Nelson) in February 2010. Seedlings were transplanted into 3.78 L pots containing sunshine mix #4 (Sun Gro Horticulture Canada), and were subject to treatment during their second growth cycle. The plants were watered every two to three days in a growth chamber under the following conditions: 20 °C, 20-25 % humidity, 0.5 g/L fertilizer (20-20-20) twice per week, and full-spectrum fluorescent lighting lamps for 16 h light / 8 h dark cycle.. At the onset of the experiment, trees were either (1) exposed to water deficit conditions by withholding water for 2 weeks prior to harvest, or (2) wounded by incising the bark with a razor blade every 5 mm along the stem along two opposite sides, and harvesting 1, 2, 4, or 8 days following the wound treatment. Needles, whole stems, and roots were rapidly harvested.  A total of 11 seedlings (1-2 replicates per treatment) were harvested, and each replicate is assumed to be a distinct genotype.  Harvested tissues were frozen in liquid nitrogen immediately following collection and stored at -80 °C until RNA extraction.