Integrated Metabolomics for Large-Scale Rice Bioresources

Plant metabolites have important biological activity for plant physiology and promoting human health. Thus, extensive detections of metabolites are important for metabolic breeding on agricultural plants. To elucidate the broad metabolite accumulation patent in plant, we established the un-targeted and targeted metabolomics based on LC-MS/MS [1, 2]. Using rice bioresources distributed from National Bioresource Project (http://www.shigen.nig.ac.jp/rice/oryzabaseV4/), we successfully detected more than 200 known and unknown metabolites in 576 samples: 192 experimental groups (32 accessions x 6 developmental stages) in 3 analytical replicates. Principal component analysis (PCA) was conducted by the metabolome data. Using score plot, the Principal component 1 and 2 were clearly separated the seed, leaf and flower samples. The co-accumulation patterns of metabolite pairs were analysed based on Pearson's product-moment correlation coefficient. We found that co-accumulated metabolites often belong to the same metabolite classes, e.g. amino acids, sugars, and flavonoids. These results have great potential for systematic metabolic breeding in rice. For the next step, we intend to identify the metabolite quantitative trait loci for broad range of rice metabolites by integrated analyses with transcriptome and genome data.

[1] Sawada et al., Phytochemistry 82: 38-45 (2012)

[2] Sawada and Hirai, CSBJ 4: e201301011 (2013)