Transcriptome and proteome analysis of gene expression differences and functional verification of anthocyanin synthesis pathway in Rhododendron

Rhododendron is one of the most diverse woody plants in the world. Because of its beautiful flower color, it is commonly used in landscaping and indoor ornamental planting. Rhododendron is rich in germplasm resources, but the molecular regulation of Rhododendron color is not well understood. In this study, two Belgian Rhododendron varieties with red and white flowers were used for RNA-seq and protein-seq analysis. Integrative analysis of transcriptome and proteome data was used to identify anthocyanin synthesis genes and proteins specifically expressed in flowers of different color. The key differences between red and white flowers, along with flower development were analyzed using the KEGG and GO databases, while the expression levels of differentially expressed genes in the anthocyanin/flavonoid biosynthesis pathways were compared using RNAseq and qRT-PCR data. The key pathways affecting the flower color in Rhododendron were found by correlation analysis of the transcriptome data, and we identified 6 anthocyanin biosynthesis-related genes. The differences in the gene sequences of CHS, CHI, F3H,FLS, DFR, ANS and cis-acting elements may be related to the accumulation of anthocyanins, resulting in the difference in Rhododendron color. Following overexpression of the DFR gene in Arabidopsis,It was found that overexpression of DFR gene can cause Arabidopsis leaves to turn red.