The Mystery of Blue Flowers: Sequencing and Analysis of the Cornflower Genome

Chiara Dassow ¹, Boas Pucker ²

SynBio2024-Team, Plant Biotechnology and Bioinformatics, Institute of Plant Biology & BRICS, TU Braunschweig, 38106 Braunschweig,Germany ¹, Plant Biotechnology and Bioinformatics, Institute of Plant Biology & BRICS,TU Braunschweig,38106 Braunschweig,Germany ²

Blue flower colouration in plants has fascinated researchers for centuries and remains a subject of great interest in plant biology. The most prominent mechanism responsible for blue flower colouration is the usage of an anthocyanin, delphinidin. Only a few species have been described to have blue flower colouration due to the formation of a metal ion complex and no genetic data seems available. An example of this is the cornflower (Centaurea cyanus). In this study, we employed Oxford Nanopore Technology (ONT) to sequence the cornflower genome, providing a comprehensive framework for genetic exploration. The sequencing data were used to assemble a high-quality reference genome sequence, enabling the detailed analysis of gene networks associated with pigment biosynthesis and metal ion complexation. Basecalling was performed with Dorado, and long reads were corrected with HERRO. The assembly had a genome size of 721 Mbp, 391 contigs, an N50 of 16.35 Mbp and a BUSCO score of 98.8 %. Structural annotation was achieved with GeMoMa with a total number of 28,763 genes. A customized annotation pipeline was applied to identify the key genes for the flavonoid biosynthesis pathway, shedding light on the molecular processes that govern this unique colouration. Our results highlight specific genes implicated in the biosynthesis of anthocyanins (e.g. bHLH42:CC08661, ANS: CC18886, F3H: CC10283) and specific transferases that are critical for the linkages of side chains to the flavonoid structure, which are needed for the formation of the metal ion complex (e.g. Glycosyltransferase: CC25081, Malonylglycosyltransferase: CC12466). This research not only advances our understanding of the genetic and molecular basis of blue flower colouration but also provides a valuable genomic resource for future studies on the cornflower and related species. The elucidation of these mechanisms has implications for fields ranging from ornamental horticulture to synthetic biology, where recreating or enhancing blue pigmentation remains a significant challenge.

Main author career stage: Bachelor student

Contribution type: Poster

First choice session: 5. Genetics, genomics, and bioinformatics

Second choice session: 4. Structure, physiology, and development