Multi-platform metabolomic approaches for tomato: GC- and LC-QqQ-MS Analyses

Metabolite accumulation patterns are known to be linked to board plant physiologies. Thus, monitoring for broad range of metabolites will allow us to identify practical biomarkers. The use of mass spectrometry (MS)-based metabolomics platform will be an efficient approach for metabolic marker construction. The selected reaction monitoring (SRM) based on standard compounds using tandem quadrupole (QqQ)-MS is suitable for high-sensitivity metabolite detection. More than 1000 conditions based on the SRM and retention time (RT) of standard compounds can be tested by integrated analyses of GC- and LC-QqQ-MS. In this study, tomato leaves were subjected to the widely targeted metabolomics as follows. The tomato leaves were lyophilized and powdered by a mixer mill. The metabolites were extracted from the powdered samples by 80% methanol with 0.1% formic acid. The dried-up extracts were dissolved in LC-MS grade pure water and subjected to LC-QqQ-MS analysis. The solutions were also applied to GC-QqQ-MS analysis after the trimethylsilylation derivatization. These analyses can detect carbohydrates, sugar phosphates, amino acids, organic acids, nucleotides, flavonoids, terpenoids, etc. The 475 and 526 SRM-RT conditions were used for GC- and LC-QqQ-MS, respectively. Total 213 metabolites were detected by the following criterion: signal to noise ratio <5 and relative standard deviation >30%. The accumulation patterns of these metabolites are thought to be connected to the various agricultural traits, and metabolic markers useful for improvement of crop quality and yields will be identified. This study was supported by the Cross-ministerial Strategic Innovation Promotion Program of the Cabinet Office, Government of Japan.