Uncovering hidden variation in polyploid wheat.

Area of Science:

• Plant genetics
• Crop science
• Genomics

Background:

• Polyploid crops often lack comprehensive reverse genetic resources needed for gene function studies.
• High sequence identity in polyploid genomes, like wheat, masks recessive allele effects.
• Wheat's tolerance to induced mutations was exploited to generate extensive genetic variation.

Purpose of the Study:

• To create and sequence a large collection of mutant lines in polyploid wheat (tetraploid and hexaploid).
• To catalog millions of mutations within the protein-coding regions of wheat genes.
• To enable the identification of previously hidden genetic variations in polyploid crops.

Main Methods:

• Generated and sequenced 2,735 mutant lines of tetraploid and hexaploid wheat.
• Cataloged over 10 million mutations in protein-coding regions.
• Analyzed mutation density and identified missense and truncation alleles per gene.

Main Results:

• Detected an average of 2,705 (tetraploid) and 5,351 (hexaploid) mutations per line.
• Achieved mutation densities of 35-40 mutations per kilobase.
• Identified an average of 23-24 missense and truncation alleles per gene, with >90% of genes having at least one deleterious mutation.

Conclusions:

• The generated public collection of mutant wheat stocks and sequence data facilitates rapid mutation identification across gene copies.
• This resource aids in uncovering hidden genetic variation in polyploid wheat.
• The developed strategy and methods are applicable to other polyploid crops, advancing plant evolution research.