Seeds of Pisum sativum L. cv Alaska Early: non-aged controls vs. Aged

Seeds of Pisum sativum L. cv Alaska Early (purchased from the ‘Abundant Life Seed Foundation’, Port Townsend, USA) were equilibrated for approximately 5 weeks in tightly sealed boxes over 300 g-1 non-saturated LiCl (Hay et al. 2008), producing 60% relative humidity, in a temperature-controlled room (20 ± 1 ºC) until their water potential was stable at 12 % MC. Relative humidity was recorded with a Rotronic AWVC-D10 Hygropalm. These equilibrated seeds are referred to as 0 day ‘non-aged controls’. Following equilibration, accelerated ageing was carried out by placing seeds in sealed bottles at 50 °C until viability loss, thereafter referred to as ‘ageing’. Samples were taken at intervals after 8, 12, and 15 days of ageing. At each interval, germination tests were performed on 1 % water agar at 25 °C under warm white fluorescent light (15 micromol m-2 s-1) at a day / night cycle (8/16h). Germination was defined as radical emergence by at least 2 mm. To summarize, we have performed a transcriptional profiling of Pisum sativum seeds comparing 0 day ‘non-aged controls’ with 8, 12 and 15 days of artificially aged seeds. Four-condition experiment, 0 days, 8 days, 12 days and 15 days. Biological replicates: 3 for each comparison. Each biological replicate was independently grown and harvested.