The structures of fairy chemicals and their derivatives, and the novel purine metabolic pathway in rice. The routes indicated by black arrows were adapted from the KEGG (Kyoto Encyclopedia of Genes and Genomes) and those indicated by dash arrows were not clear in the plant. The blue straight arrows and structures show the pathway and metabolites found in the previous study5,7. The novel pathway found in this study and the compounds whose endogenous existence have proven in this study are described in red. AHX: 2-azahypoxanthine, AICA: 5-aminoimidazole-4-carboxamide, AICAR: AICA ribonucleotide, AOH: 2-aza-8-oxohypoxanthine, FAICAR: 5-formamidoimidazole-4-carboxamide ribonucleotide, ICA: imidazole-4-carboxamide, IMP: inosine monophosphate, PRPP: phosphoribosyl diphosphate, XMP: xanthosine monophosphate.