• Controlled spatiotemporal cell division and expansion are responsible for floral bilateral symmetry. Genetic studies have pointed to class II TCP genes as major regulators of cell division and floral patterning in model core eudicots.
• Here we study their evolution in perianth‐bearing Piperales and their expression in Aristolochia, a rare occurrence of bilateral perianth outside eudicots and monocots.
• The evolution of class II TCP genes reveals single‐copy CYCLOIDEA‐like genes and three paralogs of CINCINNATA (CIN) in early diverging angiosperms. All class II TCP genes have independently duplicated in Aristolochia subgenus Siphisia. Also CIN2 genes duplicated before the diversification of Saruma and Asarum. Sequence analysis shows that CIN1 and CIN3 share motifs with Cyclin proteins and CIN2 genes have lost the miRNA319a binding site.
• Expression analyses of all paralogs of class II TCP genes in Aristolochia fimbriata point to a role of CYC and CIN genes in maintaining differential perianth expansion during mid‐ and late flower developmental stages by promoting cell division in the distal and ventral portion of the limb. It is likely that class II TCP genes also contribute to cell division in the leaf, the gynoecium and the ovules in A. fimbriata.

中文翻译：

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花被含花椒中II类TCP基因的进化及其对马兜铃属双侧花萼的贡献。

• 受控的时空细胞分裂和扩展负责花的双边对称性。遗传研究指出，II类TCP基因是模型核心双子叶植物中细胞分裂和花卉图案的主要调节剂。
• 在这里，我们研究了它们在花被器中的变态及其在马兜铃属中的表达，马兜铃属在双子叶植物和单子叶植物中很少见到双侧花被。
• II类TCP基因的进化揭示了单发CYCLOIDEA样基因和早期发散的被子植物中的3个CINCINNATA（CIN）旁系同源物。所有II类TCP基因在马兜铃亚属Siphisia中独立地复制。此外CIN2基因的多样化之前复制马蹄和细辛。序列分析表明，CIN1和CIN3与细胞周期蛋白共享基序，CIN2基因丢失了miRNA319a结合位点。
• 在马兜铃菌中所有II类TCP基因的旁系同源物的表达分析表明，CYC和CIN基因在花发育的中后期通过促进肢体远端和腹侧部分的细胞分裂，在维持不同的花期扩张中起作用。II类TCP基因也可能有助于A中叶片，妇科和胚珠的细胞分裂。菌毛。