Transcriptomic and proteomic analyses of gene expression differences and functional verification of the anthocyanin synthesis pathway in Rhododendron

Abstract

Abstract Rhododendron(Rhododendron simsii Planch) is one of the most diverse genera of woody plants in the world. It is rich in germplasm resources, but the molecular regulation of Rhododendron colour formation is poorly understood. In this study, two Belgian Rhododendron varieties with red and white flowers were subjected to RNA-sequencing and Protein sequencing analyses. Integrative analysis of transcriptome and proteome data was used to identify anthocyanin synthesis genes and proteins specifically expressed in flowers of different colours. The key differences between red and white flowers across flower development stages were analysed using the KEGG database, while the expression levels of differentially expressed genes in the anthocyanin/flavonoid biosynthesis pathways were compared using RNA-seq and qRT‒PCR data. The key pathways affecting flower colour in Rhododendron were identified by correlation analysis of the transcriptome data. We identified 6 anthocyanin biosynthesis-related genes. The differences in the gene sequences of RsCHS, RsCHI, RsF3H, RsFLS, RsDFR, and RsANS and cis-acting elements might be related to the accumulation of anthocyanins. RsDFR gene overexpression caused Arabidopsis leaves to turn red. These results provide valuable information on the molecular mechanism underlying Rhododendron flower colour formation.