Broomcorn millet (Panicum miliaceum L.), which was domesticated on the Loess Plateau of Northern China as early as 10,000 years ago, has the highest water-use efficiency among all cereal crops, i.e. the highest amount of grains produced with the same amount of water.
Until ~3000 years ago, broomcorn millet together with foxtail millet was the staple crop in Northern China. In a recent study published in Nature Communications, a research team led by Dr. ZHANG Heng and Dr. ZHU Jiankang from Shanghai Center for Plant Stress Biology of Chinese Academy of Sciences have sequenced the genome of broomcorn millet.
The genome sequence serves as a valuable resource for breeders. It provides the foundation for studying the exceptional stress tolerance as well as C4 biology in broomcorn millet.
Researchers achieved a chromosome-scale assembly of the broomcorn millet genome through a combination of single-molecule long-read sequencing (PacBio), short-read sequencing (Illumina), Hi-C and a high-density genetic map.
They found that the single-molecule long-read sequencing and the genetic map composed of 220,000 genetic markers are crucial for the high-quality genome assembly.
According to this study, genome annotation identified 55,930 protein-coding genes and 339 microRNA genes, and gene family analyses revealed a strongly expanded broad complex/tramtrack/bric-a-brac (BTB) subfamily of ubiquitin E3 ligases in Paniceae.
In addition, the analyses of C4 photosynthesis genes suggested that different subtypes of C4 carbon fixation may coexist in broomcorn millet to help it better cope with fluctuating environments in the field.