Abstract
The metabolic profile of rice plant (Oryza sativa, 2 weeks after germination) was compared between wild-type (cv. Nipponbare) and the transgenic rice lines expressing OASA1D, a gene encoding a feedback-insensitive alpha subunit of anthranilate synthase. Profiling by HPLC-PDA revealed that only a limited change in the composition of major aromatic compounds occurred in OASA1D transgenic rice lines, with the exception of a marked increase in the amount of tryptophan. A more detailed survey using HPLC-ESI-Q-MS allowed the detection of a total of 1600 metabolite peaks. Data mining by a combination of correlation analysis, ANOVA and independent component analysis revealed the relatively small but significant changes for about 20 minor metabolites. LC-MS/MS analysis demonstrated that the metabolites that increased in quantity by the expression of OASA1D included such indole compounds as γ-glutamyltryptophan.
