The double-flower phenotype has been selected by humans for its attractiveness in various plant species and it is of great commercial value for the ornamental market. In this study we investigated the genetic determinant of the dominant double-flower trait in carnation, petunia, and Rosa rugosa, and identified mutant alleles of TARGET OF EAT (TOE)-type genes characterized by a disruption of the miR172 target sequence and of the C-terminal portion of the encoded protein. Despite the phylogenetic distance between these eudicots, which diverged in the early Cretaceous, the orthologous genes carrying these mutations all belong to a single TOE-type subgroup, which we name as PETALOSA (PET). Homology searches allowed us to identify PET sequences in various other species. To confirm the results from naturally occurring mutations, we used CrispR-Cas9 to induce lesions within the miR172 target site of Nicotiana tabacum PET genes, and this resulted in the development of supernumerary petaloid structures. This study describes pet alleles in economically important ornamental species and provides evidence about the possibility of identifying and engineering PET genes to obtain the desirable double-flower trait in different plants.

中文翻译：

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直系同源 PETALOSA TOE 型基因的突变导致在系统发育上较远的真双子叶植物中出现显性的双花表型。

重瓣花表型因其在各种植物物种中的吸引力而被人类选择，对观赏市场具有巨大的商业价值。在这项研究中，我们调查了康乃馨、矮牵牛和蔷薇的显性双花性状的遗传决定因素，并鉴定了以 miR172 靶序列和编码蛋白质的 C 末端部分。尽管这些真双子叶植物之间的系统发育距离在白垩纪早期发生了分歧，但携带这些突变的直系同源基因都属于一个单一的 TOE 型亚群，我们将其命名为 PETALOSA (PET)。同源性搜索使我们能够识别各种其他物种的 PET 序列。为了确认自然发生突变的结果，我们使用 CrispR-Cas9 在烟草 PET 基因的 miR172 靶位点内诱导病变，这导致了多余的花瓣状结构的发展。这项研究描述了经济上重要的观赏物种中的宠物等位基因，并提供了关于识别和改造 PET 基因以获得不同植物中理想的双花性状的可能性的证据。