Floral zygomorphy (monosymmetry) is a key innovation in flowering plants and is related to the coevolution of plants and their animal pollinators. The molecular basis underlying floral zygomorphy has been analyzed, and two regulatory pathways have been identified: one determines the dorsoventral (DV) asymmetry along the floral plan, and the other controls organ internal (IN) asymmetry during petal development. While strides have been made to understand the molecular mechanism controlling DV asymmetry, which mainly involves an interplay between TCP and MYB transcription factors, the molecular pathway regulating IN asymmetry remains largely unknown. In this review, we discuss what is known about regulators and the molecular pathway regulating IN asymmetry. Our analysis revealed that the regulation of IN asymmetry occurs at the cellular, tissue, and organ genesis levels during petal development and that the regulatory mechanism is likely integrated into different developmental paths, such as floral and root nodule development. Although the molecular regulation of IN asymmetry is not be a linear path, a key hub for the regulatory network could be vascular patterning during petal organogenesis.

中文翻译：

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花瓣发育过程中器官内部（IN）不对称控制的分子机制研究

花的对称性（单对称）是开花植物的一项关键创新，与植物及其动物传粉者的共同进化有关。分析了花对称性的分子基础，并确定了两条调控途径：一条决定沿花计划的背腹 (DV) 不对称，另一条控制花瓣发育过程中的器官内部 (IN) 不对称。虽然在理解控制 DV 不对称性的分子机制方面取得了长足进步，主要涉及 TCP 和 MYB 转录因子之间的相互作用，但调节 IN 不对称性的分子途径仍然很大程度上未知。在这篇综述中，我们讨论了关于调节剂和调节 IN 不对称性的分子途径的已知信息。我们的分析表明，IN 不对称性的调节发生在细胞、组织、和花瓣发育过程中的器官发生水平，并且调节机制可能整合到不同的发育路径中，例如花和根瘤发育。尽管 IN 不对称性的分子调控不是线性路径，但调控网络的一个关键枢纽可能是花瓣器官发生过程中的血管模式。