A comprehensive omics resource and genetic tools for functional genomics research and genetic improvement of sorghum.

Abstract

Sorghum, the fifth most important food crop globally, serves not only as a source of silage forage, fiber, syrup, and biofuel, but also is widely recognized as an ideal model crop for studying stress biology due to its exceptional ability to tolerate multiple abiotic stresses, including high salt-alkali conditions, drought, and heat. However, conducting functional genomics studies on sorghum has been challenging, primarily due to the limited availability of genetic resources and effective genetic transformation techniques. In this study, we developed a comprehensive and systematic resource platform (https://sorghum.genetics.ac.cn/SGMD) aiming to advance the genetic understanding of sorghum. Our effort encompassed a telomere-to-telomere (T2T) genome assembly of an inbred sorghum line, E048, yielding 729.46 Mb of sequence data representing the complete genome. Alongside the high-quality sequence data, a gene-expression atlas covering 13 distinct tissues was developed. Furthermore, we constructed a saturated ethyl methane sulfonate (EMS) mutant library, comprising 13,226 independent mutants. Causal genes in chlorosis and leafy mutants from the library were easily identified by leveraging the MutMap and MutMap+ methodologies, demonstrating the powerful application of this library for identifying functional genes. To further facilitate the sorghum research community, we performed whole-genome sequencing (WGS) of 179 M₂ mutant lines, resulting a total of 2,291,074 mutations that covered 97.54% of all genes. In addition, an Agrobacterium-mediated sorghum transformation platform was established for gene function studies. In summary, this work established a comprehensive platform, providing valuable resources for functional genomics investigations and genetic improvement of sorghum.