Non-targeted Metabolite Profiling by GC-MS

Non-targeted metabolite profiling was carried out by GC-MS using a modified method described by Yun et al. [29 (link)] and Tan et al. [68 ]. In summary, 200 mg flower samples were extracted in 2, 700 μl methanol and ribitol solution (300 μl, 0.2 mg ml^− 1) was added as a quantification internal standard. The mixture was incubated firstly, then agitated, dried and derivatized. GC-MS analysis was performed by using a Thermo Trace GC Ultra, together with a Thermo Fisher TSQ 8000 Evo Triple Quadrupole mass spectrometer (Thermo Fisher Scientific, Waltham, MA, USA) as suggested by Yun et al. [29 (link)] and Tan et al. [68 ]. Metabolites were identified by searching in the NIST library. Quantification was based on the peak area ratios of the quantitation ions and the internal standard ribitol as described by Tan et al. [68 ].