In rice (Oryza sativa L.), floral organ development is an important trait. Although a role for PINOID in regulating floral organ development was reported recently, the underlying molecular mechanism remains unclear. Here, we isolated and characterized an abnormal floral organ mutant and mapped the causative gene through an improved MutMap method. Molecular study revealed that the observed phenotype is caused by a point mutation in OsPINOID (OsPID ) gene; therefore, we named the mutation as ospid‐4 . Our data demonstrate that OsPID interacts with OsPIN1a and OsPIN1b to regulate polar auxin transport as shown previously. Additionally, OsPID also interacts with OsMADS16 to regulate transcription during floral organ development in rice. Together, we propose a model that OsPID regulates floral organ development by modulating auxin polar transport and interaction with OsMADS16 and/or LAX1 in rice. These results provide a novel insight into the role of OsPID in regulating floral organ development of rice, especially in stigma development, which would be useful for genetic improvement of high‐yield breeding of rice.

中文翻译：

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PINOID通过调节植物生长素的运输来调节花器官的发育，并与水稻中的MADS16相互作用。

在水稻（Oryza sativa L.）中，花器官发育是重要的性状。尽管最近报道了PINOID在调节花器官发育中的作用，但其潜在的分子机制仍不清楚。在这里，我们分离并表征了异常的花器官突变体，并通过改进的MutMap方法绘制了致病基因。分子研究表明，观察到的表型是由OsPINOID（OsPID）基因的点突变引起的。因此，我们将突变命名为ospid‐4。我们的数据表明，OsPID与OsPIN1a和OsPIN1b相互作用以调节极性植物生长素的转运，如前所述。此外，OsPID还与OsMADS16相互作用以调节水稻花器官发育过程中的转录。在一起，我们提出了一个模型，即OsPID通过调节植物生长素极性转运以及与水稻中OsMADS16和/或LAX1的相互作用来调节花器官发育。这些结果为OsPID在调节水稻花器官发育，特别是在柱头发育中的作用提供了新的见解，这将有助于水稻高产育种的遗传改良。