Supporting data for "Transcriptional regulation of flavone biosynthesis in rice"

Flavones, a major flavonoid subclass, are abundantly accumulated in monocots and they are commonly present in the forms of flavone C-glycosides and O-conjugated flavones. In rice, the biosynthetic pathways of flavone and flavone C-glycosides are well characterized, but the transcriptional regulation of key enzymes remained largely unknown. This study characterizes the MYB transcription factors involved in the regulation of flavone and flavone C-glycoside biosynthesis genes in rice.In rice, chalcone synthase (OsCHS1) initiates flavonoid biosynthesis by producing naringenin chalcone. Whether OsCHS1 is continuously expressed spanning the rice life cycle was unclear. In this study, a systematic analysis of the expression of OsCHS1 was carried out using the non-invasive RUBY reporter system. The formation of red betalain indicates the expressionof OsCHS1, and the results presented in "Figures_chapter2.pptx" suggest the tissue-specific and stage-specific expression patterns of OsCHS1. Meanwhile, transient overexpression in rice protoplasts identified various culm-expressed R2R3-MYB proteins, functioning as higher hierarchical regulators for the expression of OsCHS1 and flavone biosynthesis genes, and their transcriptional activities are described in "Figures_chapter2.pptx" and "Dataset_chapter2".This study also characterizes the role of OsMYB58/63 in the regulation of flavone biosynthesis. The files "Figures_chapter3.pptx" and "Dataset_chapter3.xlsx" include the results of gene expression analysis, metabolitc analysis, dual-luciferase reporter assays and in vitro protein-DNA binding assays which explain how OsMYB58/63 functions as transcriptional activator in regulating flavone biosynthesis. Moreover, the data in the file "Dataset_Supplementary.xlsx" suggest the multifunctional roles of OsMYB58/63 in regulating specialized metabolism in rice.Lastly, this study characterizes a R2R3-MYB protein, OsP1L, as a transcriptional activator of the flavone C-glycoside biosynthesis in rice. The files "Figures_chapter4.pptx" and "Dataset_chapter4.xlsx" include the results of gene expression analysis, DAP-seq analysis, dual-luciferase reporter assays and EMSA which elucidate how OsP1L regulates the expression of OsCHI, OsCYP93G2 and OsCYP75B3. Moreover, these files include the expression patterns of flavone C-glycoside biosynthesis genes and the metabolic analysis of flavone C-glycosides in various tissues.