Dynamic Transcriptome Changes Driven by the Mutation of OsCOP1 Underlie Flavonoid Biosynthesis and Embryogenesis in the Developing Rice Seed

Abstract CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1), an E3 ubiquitin ligase, functions as a central repressor of light signaling and regulates various light-mediated developmental metabolic processes in plants. However, detailed mechanisms underlying COP1-regulated flavonoid biosynthesis embryogenesis rice seeds remain largely unknown. Here, we performed transcriptome analysis the cop1 ( yellowish - pericarp embryo lethal [ yel ]) null mutant, characterized by accumulation abnormal development embryo, to identify profile expression genes involved development. Comparative yel-hc wild-type revealed 979 differentially expressed (DEGs), which 577 were upregulated 402 downregulated hc seeds. Functional annotation DEGs that mainly enriched ‘metabolism’, ‘transcription factors’, ‘secondary metabolites’, ‘flavonoid biosynthesis’. The encoding AP2-EREBP, MYB, bZIP transcription factors (TFs) predominantly upregulated, whereas those HB, bHLH, ABI3VP1 TFs gene C -glycosyl flavone pathway, including OsP1 , activated, anthocyanin showed no significant change expression. In addition, transcript levels development-related genes, especially homeobox auxin regulation well somatic embryogenesis-related significantly . Taken together, these results indicate OsCOP1 plays crucial role structure formation, changes signal transduction-related could have impact on seed.