Increased and ectopic expression of Triticum polonicum VRT-A2 underlies elongated glumes and grains in hexaploid wheat in a dosage-dependent manner
Increased and ectopic expression of Triticum polonicum VRT-A2 underlies elongated glumes and grains in hexaploid wheat in a dosage-dependent manner
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小麦 VRT-A2 的增加和异位表达是六倍体小麦中颖片和籽粒伸长的基础，且呈剂量依赖性
DOI：
10.1101/2020.11.09.375154
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Adamski N
中科院分区：
文献类型：
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作者：
Adamski N
花的发育是作物产量的主要决定因素。在小麦中，小穗和花器官大小的自然变异在波兰小麦中特别明显，波兰小麦是小麦的一个四倍体亚种，具有长颖片、外稃和籽粒。利用图位克隆技术，我们鉴定了VRT 2，一个属于SV家族的MADS盒转录因子，作为T. polonicumlong-glume（P1）位点。钙调素P1突变是内含子1的序列重排，导致T的表达增加和异位表达。Polonicum VRT-A2等位基因。基于等位基因变异研究，我们认为VRT-A2的内含子-1突变是唯一的T。polonicum物种定义多态性，后来通过自然杂交引入六倍体小麦。不同P1位点的近等基因系显示P1在小花间的梯度效应。转T. Polonicum VRT-A2等位基因的分析表明，VRT-A2的表达水平与穗、颖片、籽粒和花器官长度高度相关。这些结果强调了表达谱的变化如何通过变异切割调节以剂量依赖性方式影响多倍体作物的农艺性状。一句话总结MADS盒转录因子VRT-A2中的内含子1重排导致其错误表达并定义了波兰小麦的长颖表型（T. polonicum）。
Flower development is a major determinant of yield in crops. In wheat, natural variation for the size of spikelet and floral organs is particularly evident inTriticum polonicum, a tetraploid subspecies of wheat with long glumes, lemmas, and grains. Using map-based cloning, we identifiedVRT2, a MADS-box transcription factor belonging to theSVPfamily, as the gene underlying theT. polonicumlong-glume (P1)locus. The causalP1mutation is a sequence re-arrangement in intron-1 that results in both increased and ectopic expression of theT. polonicum VRT-A2allele. Based on allelic variation studies, we propose that the intron-1 mutation inVRT-A2is the uniqueT. polonicumspecies defining polymorphism, which was later introduced into hexaploid wheat via natural hybridizations. Near-isogenic lines differing for theP1locus revealed a gradient effect ofP1across florets. Transgenic lines of hexaploid wheat carrying theT. polonicum VRT-A2allele show that expression levels ofVRT-A2are highly correlated with spike, glume, grain, and floral organ length. These results highlight how changes in expression profiles, through variation incis-regulation, can impact on agronomic traits in a dosage-dependent manner in polyploid crops.One-sentence summaryAn intron-1 rearrangement in the MADS-box transcription factorVRT-A2leads to its misexpression and defines the long-glume phenotype of Polish wheat (T. polonicum).