The advantages of free threshing in wheat led to the selection of the domesticated allele, which is now present in almost all modern wheat varieties. and the pre-domestication allele, , encode an AP2 transcription factor, with the domesticated allele conferring a free-threshing character and a subcompact (i.e. partially compact) inflorescence (spike). We demonstrate that mutations in the miR172 binding site of the gene are sufficient to increase transcript levels via a reduction in miRNA-dependent degradation, consistent with the conclusion that a single nucleotide polymorphism in the miRNA binding site of relative to was essential in defining the modern allele. We describe novel gain- and loss-of-function alleles of and use these to define new roles for this gene in spike development. is required for the suppression of 'sham ramification', and increased Q expression can lead to the formation of ectopic florets and spikelets (specialized inflorescence branches that bear florets and grains), resulting in a deviation from the canonical spike and spikelet structures of domesticated wheat.