Homoeolog expression in polyploid wheat mutants shows limited transcriptional compensation

Active transcriptional compensation between gene duplicates (paralogs or homoeologs) has been proposed to facilitate functional redundancy, whereby mutations in multiple gene copies are required before a phenotype is observed. We tested whether transcriptional compensation occurs between homoeologs in response to premature termination codon (PTC) mutations in mutagenised wheat lines. Only ∼3% of cases showed homoeologous upregulation in response to PTC mutations, suggesting that there is no widespread active transcriptional compensation between wheat homoeologs.