2.3 Analysis of primary metabolites by Gas chromatography–mass
spectrometry (GC-MS)
GC-MS-based strategy was used to determine the metabolome profiles of
the roots of two-day-old seedling after 6, 12, 24, 48 and 72 h of
control and 5 μM Al treatments and subsequent 2, 6, 12 and 24 h of 150
μM phosphate addition (Lisec et al., 2006). The samples were analyzed by
7890A/5975C GC-MS equipped with HP-5 capillary column (Agilent, USA).
Helium was used as a carrier gas at a flow rate of 1 ml
min-1. After injection, the temperature was maintained
at 80 °C for 2 min, followed by 5 °C per min ramp to 300 °C, and was
then set at 300 °C for 10 min. Mass spectra were recorded with a
mass-to-charge ratio of 70 to 600 atomic mass units scanning range. The
raw data was processed with AMDIS software (http://chemdata.nist.gov/).
The relative metabolite level was calculated as log2transformed ratio of metabolite concentration under Al treatment (or P
addition) to metabolite concentration under control condition (control
was sampled at each time point). Experiments were conducted with four
biological replicates.