Analysis of stress signaling and seed dormancy-related phytohormones
For each treatment (n=3 plants), 50mg of ground seeds were used to quantify 2-cis , 4-trans -abscisic acid (ABA), gibberellic acid (GA3), indole-3-acetic acid (IAA), jasmonic acid (JA), and salicylic acid (SA). Previously freeze-dried samples were mixed with 500 µL of extraction solvent [2-propanol/H2O/ concentrated HCl (2:1:0.002, v/v/v)] and then analyzed by HPLC-MS as described in Pan, Welti & Wang (2010). Because the dynamics of ABA and GA3 controls the balance between germination and dormancy, the ABA:GA3 ratio was used as a proxy for seed dormancy: germination balance (Debeaujon & Koornneef 2000; Finkelstein 2013).