Helianthus annuus cultivar:HA412 Genome sequencing. Helianthus annuus cultivar:HA412

The HA412 sunflower genome represents a significant advancement in understanding the sunflower, Helianthus annuus L., a major global oil crop known for its resilience and adaptability to climate change, including drought conditions. The comprehensive reference for the sunflower genome, which is approximately 3.6 gigabases in size, includes extensive transcriptomic data from various plant organs. This genome, largely consisting of closely related sequences, was assembled using single-molecule real-time sequencing technologies. Its analysis has shed light on the evolutionary history of the Asterids, revealing a whole-genome triplication at the base of the Asterids II clade and a sunflower-specific whole-genome duplication about 29 million years ago.The genome has facilitated the development of gene networks for key breeding traits like flowering time and oil metabolism, unveiling new candidate genes within these networks. The genomic architecture of flowering time, in particular, is shaped by the latest whole-genome duplication, indicating that ancient paralogues can remain in regulatory networks for millions of years. Additionally, the genome plays a central role in understanding oil metabolism, with a reconstructed genome-scale metabolic network for sunflower including 429 genes mapped onto 125 reactions across 12 pathways.The availability of this reference genome and its accompanying resources enhances the sunflower's role as a model for ecological and evolutionary studies. It also accelerates breeding programs, enabling precision breeding through marker-assisted and genomic selection. The genome-wide association studies (GWAS) of flowering time and other traits offer insights into the molecular mechanisms underlying trait variation, reinforcing the sunflower's potential as a model crop for climate change adaptation. This adaptation is envisioned through the exploitation of genome-enabled systems biology and multidisciplinary analyses of interactions between abiotic stressors, pathogen attacks, and agronomic practices