A Sorghum Mutant Resource as an Efficient Platform for Gene Discovery in Grasses

Area of Science:

• Plant genetics
• Crop science
• Genomics

Background:

• Sorghum (Sorghum bicolor) is a vital C4 crop and a model organism for Poaceae research.
• Functional gene validation in sorghum is hindered by limited genomic and germplasm resources for induced mutation analysis.

Purpose of the Study:

• To develop a comprehensive, sequenced mutant resource for sorghum (Sorghum bicolor).
• To facilitate efficient functional gene validation and accelerate sorghum breeding programs.

Main Methods:

• Generated 6400 pedigreed M4 mutant pools from EMS-mutagenized BTx623 sorghum seeds via single-seed descent.
• Performed whole-genome sequencing on 256 phenotyped mutant lines.
• Conducted reverse genetics to identify genes associated with drought tolerance.

Main Results:

• Sequencing identified over 1.8 million EMS-induced mutations across >95% of sorghum genes, with 97.5% distinct from natural variations.
• Identified eight genes potentially involved in drought tolerance, including allelic mutations and cosegregating mutations.
• Established a valuable sequenced sorghum mutant resource for functional genomics.

Conclusions:

• A large-scale, sequenced pedigreed mutant resource significantly enhances gene functional validation in sorghum.
• This resource accelerates sorghum breeding and facilitates the translation of findings to other Poaceae species through integrated genomics.