Researchers Decode Complete Genome of Medicinal Plant Forsythia Suspensa

A recent study has decoded the complete genome of Forsythia suspensa, a plant renowned for its medicinal value and decorative appeal. The research delivers a flawless, gap-free genome assembly, uncovering the complex architecture of centromeres vital to genetic stability. This advancement offers a detailed genetic map, setting the stage for future breakthroughs in ecological management and medical research.

Despite its traditional significance in medicine and environmental conservation, Forsythia suspensa has remained genomically elusive due to fragmented and incomplete assemblies. The centromeres, essential for chromosome segregation, are especially difficult to study because of their dense and repetitive DNA sequences. Addressing these obstacles has made a complete and accurate genome assembly an urgent goal, critical for deepening our understanding of the plant's evolutionary and genetic traits.

The study (DOI: 10.1093/hr/uhae185), led by researchers from the Institute of Genetics and Developmental Biology and other institutions, was published on July 10, 2024, in Horticulture Research. Leveraging cutting-edge Oxford Nanopore, Hi-C, and PacBio HiFi sequencing technologies, the team assembled a telomere-to-telomere (T2T) genome of Forsythia suspensa. This assembly, encompassing 14 chromosomes, features comprehensive centromere mapping and sheds new light on centromere complexity and retrotransposon behavior.

The T2T genome assembly of Forsythia suspensa spans 688.79 Mb and includes over 33,900 protein-coding genes. One of the study's highlights is the use of a specialized CENH3 antibody to map centromeres precisely, revealing a diverse array of satellite sequences with unique lengths, hinting at dynamic evolutionary mechanisms. Furthermore, researchers identified that older retrotransposons are more abundant in these centromeres compared to the rest of the genome, likely influenced by the plant's predominantly asexual reproduction. This observation stands in contrast to centromere patterns in sexually reproducing species, offering new insights into the genetic stability shaped by reproductive strategies.

Dr. Yang Liu, a principal investigator on the project, emphasized, "The gap-free genome of Forsythia suspensa is a major achievement in plant genomics. Our research not only deepens our understanding of centromere biology but also paves the way for further exploration of repetitive DNA's role in plant evolution. This comprehensive genomic resource will undoubtedly serve as a benchmark for future studies on medicinal and ecological plant species."

The significance of this genome assembly extends beyond academia. It promises to accelerate genetic research in plant breeding, ecological conservation, and biotechnology. Detailed centromere mapping could inform conservation strategies and enhance our understanding of plant resilience. Additionally, the research lays a solid foundation for unraveling the genetic underpinnings of Forsythia's medicinal qualities, with the potential to optimize and expand therapeutic applications based on the plant's bioactive compounds.