In a groundbreaking development for the agricultural and nutraceutical industries, researchers have successfully assembled the first complete, gap-free genome of *Juglans sigillata*, a highly valued nut crop known for its rich nutritional profile. This achievement, led by Delu Ning of the Central South University of Forestry and Technology and the Institute of Economic Forest at the Yunnan Academy of Forestry and Grassland, marks a significant milestone in the genetic understanding of this economically important species.
*Juglans sigillata*, commonly known as the white walnut, is celebrated for its high content of essential nutrients, antioxidants, and healthy fats, which contribute to cardiovascular, brain, and gut health. However, the lack of a complete genome assembly has historically hindered breeding efforts and genetic research. The team addressed this challenge by generating deep coverage ultralong reads using Oxford Nanopore Technology (ONT) and PacBio HiFi sequencing, resulting in a telomere-to-telomere (T2T) genome assembly that spans 537.27 Mb with an impressive completeness of 98.1%.
“This comprehensive genome assembly is a game-changer for the agricultural sector,” said Delu Ning, the lead author of the study. “It provides a solid foundation for future breeding programs and genetic research, enabling us to enhance the quality and yield of *Juglans sigillata*.”
The researchers annotated the genome using transcriptome data and homologous proteins, identifying 36,018 protein-coding genes. Additionally, they profiled global cytosine DNA methylations using ONT sequencing data, revealing high methylation levels in transposable element (TE)-rich chromosomal regions and lower methylation in gene-rich areas. This detailed methylome analysis offers valuable insights into the epigenetic regulation of the white walnut genome.
One of the most intriguing aspects of the study is the integration of multi-omics data to understand the mechanism underlying endopleura coloration. The team identified eight candidate genes, including ANR, involved in anthocyanin biosynthesis pathways, which are crucial for the development of color in plants. “Understanding the genetic basis of endopleura coloration not only enhances our knowledge of plant biology but also opens avenues for developing new varieties with desirable traits,” Ning explained.
The implications of this research extend beyond academia. For the agricultural and nutraceutical industries, the complete genome assembly and the identification of key genes involved in important traits like endopleura coloration will facilitate more efficient breeding programs and improved crop quality. This, in turn, can lead to higher yields and better nutritional profiles, benefiting both farmers and consumers.
“This study is a testament to the power of advanced sequencing technologies and multi-omics approaches in unlocking the genetic potential of economically important crops,” Ning added. “We are excited about the prospects of applying these findings to enhance the sustainability and productivity of *Juglans sigillata* cultivation.”
The research was published in the *Horticultural Plant Journal*, known in Chinese as *园艺植物学报*, providing a valuable resource for scientists, breeders, and industry professionals. As the global demand for nutritious and sustainable food sources continues to grow, this groundbreaking study paves the way for innovative developments in the field of agritech.