Draft genome assembly of the Woolly bottlebrush (Greyia radlkoferi) using Pacbio long-read sequencing technology.

Abstract

The Woolly bottlebrush (Greyia radlkoferi) is an indigenous South African plant known for its ornamental appeal and potential medicinal uses. It naturally grows on rocky hillsides and grasslands and highly resilient to drought, temperature fluctuations, and nutrient-poor soils. Its flavonoid-rich compounds with anti-tyrosinase activity support its traditional use to treat skin pigmentation disorders in humans. Despite its outstanding ecological and biochemical characteristics, no reference genome is available for Greyia radlkoferi. Therefore, this study aimed to generate the first draft genome of the Greyia Radlkofleri using PacBio Sequel IIe HiFi long read sequencing. A total of 56.07 Gb HiFi data was generated, providing a total genome coverage of 270X. The assembled genome size was 206Mb, with the longest scaffold being 13.9 Mb. The assembly statistics yielded a scaffold and contig N50 of 10.1 Mb, and an L50 of 9, and with an overall GC content of 34.9 %. The genome scope profile set at kmer = 17 indicated that the genome is triploid. The genome annotation predicted 17,804 protein-coding genes and 17,804 transcripts with an average gene length of 3,116.03 bp. This is the first draft genome of its kind for the Greyia genus and provides a foundation for future studies aimed at elucidating the genetic basis of its environmental resilience and the biosynthetic pathways underlying its medicinal properties.