The major wheat domestication allele Q (encoding an APETALA2 like transcription factor) is responsible for the free threshing and square-headed spikes of modern wheat. Wild type q and null q' alleles cause a reversal to the speltoid phenotype. Q pleiotropically affects additional yield and quality traits so genetic variation in Q and its interaction partners remain important for crop improvement. Here we report the discovery of a novel q' allele that contribute to the molecular characterization of Q. This induced mutation cause an Ala→Thr substitution at a highly conserved position in the first of two APETALA2 like domains of the Q protein. The mutation correlates with a speltoid phenotype as expected for a loss of Q function. Thus, it is demonstrated that the first APETALA2 like domain is essential for Q function. The phenotype was discovered in a mutant from an in silico TILLING population and the causative mutation could be identified in the existing sequence data. This report therefore provides an example of a forward genetic application of in silico TILLING.

中文翻译：

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一种新型小麦 q' 等位基因通过计算机 TILLING 前向遗传鉴定

主要的小麦驯化等位基因 Q（编码 APETALA2 样转录因子）负责现代小麦的自由脱粒和方头穗。野生型 q 和无效 q' 等位基因导致对 speltoid 表型的逆转。Q 多效性影响额外的产量和品质性状，因此 Q 及其相互作用伙伴的遗传变异对于作物改良仍然很重要。在这里，我们报告了一个新的 q' 等位基因的发现，该等位基因有助于 Q 的分子表征。这种诱导突变导致在 Q 蛋白的两个 APETALA2 样结构域中的第一个高度保守的位置发生 Ala→Thr 替换。该突变与 Q 功能丧失所预期的 speltoid 表型相关。因此，证明第一个 APETALA2 样域对于 Q 函数是必不可少的。该表型是在来自计算机 TILLING 群体的突变体中发现的，并且可以在现有序列数据中确定致病突变。因此，本报告提供了计算机 TILLING 正向遗传应用的示例。