Comprehensive profiling and natural variation of flavonoids in rice

• Published in: Journal of integrative plant biology 2014-09, Vol.56 (9), p.876-886
• Main Authors: Dong, Xuekui, Chen, Wei, Wang, Wensheng, Zhang, Hongyan, Liu, Xianqing, Luo, Jie
• Format: Article
• Language: English
• Subjects: Arabidopsis; biosynthesis; Chromatography, Liquid; developmental stages; Flavonoids; Flavonoids - classification; Flavonoids - metabolism; genes; germplasm; LC-MS; liquid chromatography; metabolic profiling; metabolomics; natural variation; nucleotide sequences; Oryza - metabolism; Oryza sativa; phenolic compounds; Plant Leaves - metabolism; rice; single-nucleotide polymorphisms; Tandem Mass Spectrometry; 单子叶植物; 水稻; 生物合成基因; 组织特异性; 自然变异; 酚类化合物; 黄酮类化合物
• ISSN: 1672-9072; 1744-7909
• DOI: 10.1111/jipb.12204

Flavonoids constitute a major group of plant phenolic compounds. While extensively studied in Arabidopsis, profiling and naturally occurring variation of these compounds in rice (Oryza sativa), the monocot model plant, are less reported. Using a collection of rice germplasm, comprehensive profiling and natural variation of flavonoids were presented in this report. Application of a widely targeted metabolomics method facilitated the simultaneous identification and quantification of more than 90 flavonoids using liquid chromatography tandem mass spectrometry (LC‐MS/MS). Comparing flavonoid contents in various tissues during different developmental stages revealed tissue‐specific accumulation of most flavonoids. Further investigation indicated that flavone mono‐C‐glycosides, malonylated flavonoid O‐hexosides, and some flavonoid O‐glycosides accumulated at significantly higher levels in indica than in japonica, while the opposite was observed for aromatic acylated flavone C‐hexosyl‐O‐hexosides. In contrast to the highly differential accumulation between the two subspecies, relatively small variations within subspecies were detected for most flavonoids. Besides, an association analysis between flavonoid accumulation and its biosynthetic gene sequence polymorphisms disclosed that natural variation of flavonoids was probably caused by sequence polymorphisms in the coding region of flavonoid biosynthetic genes. Our work paves the way for future dissection of biosynthesis and regulation of flavonoid pathway in rice.