Greenwood Julian R, Finnegan E Jean, Watanabe Nobuyoshi, Trevaskis Ben, Swain Steve M
CSIRO Agriculture and Food, Black Mountain Science and Innovation Park, GPO Box 1700, Canberra, Australian Capital Territory 2601, Australia.
Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia.
Development. 2017 Jun 1;144(11):1959-1965. doi: 10.1242/dev.146407. Epub 2017 Apr 28.
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.
小麦中自由脱粒的优势导致了驯化等位基因的选择，如今该等位基因几乎存在于所有现代小麦品种中。而驯化前的等位基因 编码一种AP2转录因子，驯化等位基因赋予自由脱粒特性和亚紧密（即部分紧密）的花序（穗）。我们证明， 基因的miR172结合位点发生突变足以通过减少miRNA依赖性降解来提高转录水平，这与以下结论一致：相对于 ， 的miRNA结合位点中的单核苷酸多态性对于定义现代 等位基因至关重要。我们描述了 的新的功能获得和功能丧失等位基因，并利用这些等位基因确定该基因在穗发育中的新作用。 是抑制“假分枝”所必需的，增加 的表达会导致异位小花和小穗（承载小花和籽粒的特化花序分支）的形成，从而导致与驯化小麦的典型穗和小穗结构产生偏差。
