GC-MS Analysis of Metabolites

The GC-MS was performed as previously described (Cao et al., 2020 (link)), using Gas Chromatography-Mass Spectrometer (7,890B–5977B, Agilent Technologies, CA, United States) equipped with a DB-5MS quartz capillary column (0.25 mm × 30 mm, 0.25 μm). Analysis was performed using 1 µL injection volume with helium as the carrier gas (99.999%). The flow rate was 1.0 ml/min and a split ratio of 10:1. The column temperature was maintained at 60°C for 1 min, then increased at a rate of 10°C/min up to 250°C and maintained at 250°C for 10 min. The injection temperature was 250°C, while that of the electron bombardment ion source was 230°C, with a solvent delay of 5.9 min and a scanning range of the mass spectrum at m/z 50.0–600.0.