First Gap-Free Peanut Genomes Reveal Genes for Bigger Seeds and Better Oils

An international team of researchers, led by Murdoch University, has successfully sequenced the first complete, gap-free genomes of six peanut varieties, providing a definitive blueprint for agricultural improvement. Published in Nature Genetics, this telomere-to-telomere (T2T) assembly identifies two critical genes, AhWRI1, which can increase seed oil content from 48% to 54%, and AhGSA1, which is linked to a 70% increase in seed weight.

The study overcame the immense challenge of the peanut's complex genetic structure, which contains four sets of chromosomes and vast amounts of repetitive DNA that previously left significant dark regions in its sequence. By analyzing 521 peanut accessions from across the globe, the team discovered that the two subgenomes of the cultivated peanut have evolved asymmetrically, with one half undergoing much more structural change than the other. This finding explains why certain peanut varieties, such as var. hirsuta, possess unique traits like distinct plant architecture and lipid metabolism that are absent in other subspecies like var. hypogaea.

Beyond increasing crop value, these findings hold significant implications for global food security and sustainable farming. Peanuts are a vital source of protein and oil for hundreds of millions of people, particularly in developing regions, and their nitrogen-fixing capabilities make them essential for healthy crop rotations. Professor Rajeev Varshney, Director of the Centre for Crop and Food Innovation, noted that while a gap-free human genome was only achieved four years ago, reaching this milestone for the complex peanut genome provides a transformative toolkit for creating resilient crops that can better withstand environmental shocks.

For more details, read the article in Murdoch University News.