The allopolyploid genome (e.g. AABBDD) of wheat hinders its genetic improvement through molecular tools. With the development of genome-editing comes opportunities for expanding wheat genetic diversity. Researcher Eduard Akhunov from Kansas State University and colleagues utilize CRISPR-Cas9, together with mutagenesis, to investigate the role of wheat gene TaGW2 in relation to grain traits.

CRISPR-knockout plants for the gene show increased grain size and weight, indicating a negative regulator function for TaGW2. Notably, the gene also affect the phenotype in a dose-dependent manner, that is, plants mutated at two or more genomes show greater change in phenotype than when mutated only at one genome. Using a TILLING population, the researchers further confirm that the gene is a negative regulator for grain size and weight.

For more details, read the article in Theoretical and Applied Genetics.