| Description |
A seed was disrupted using amulti beads shocker (Shake Master NEO, BMS, Tokyo, Japan), and the seed powder was extracted with 1 mL of extraction buffer (0.1% HCO2H, MeOH–H2O (4:1 v/v), and 33.6 nM lidocaine and 840 nM camphor sulfonic acid as internal standards of positive mode and negative mode, respectively) using a multi beads shocker. After centrifugation (4 ℃, 10,000 rpm, 5 min), the sample tubes were subjected to sample preparation (buffer transfer, 250 lL of seed extract; dried up, resolution, 250 lL of LC-MS grade H2O; filtration, 384 well formatted filter (0.45 lm PVDF, Whatman, NJ, USA) with a liquid handling system (Microlab Star Plus, Hamilton, Ontario, Canada) (Sawada et al., 2009a). |