The flower of Hedychium coronarium possesses highly specialized floral organs: a synsepalous calyx, petaloid staminodes and a labellum. The formation of these organs is controlled by two gene categories: floral organ identity genes and organ boundary genes, which may function individually or jointly during flower development. Although the floral organogenesis of H. coronarium has been studied at the morphological level, the underlying molecular mechanisms involved in particular organ morphologies that emerge in flower development still remain poorly understood. Here, we used comparative transcriptomics combined with Real-time quantitative PCR to investigate gene expression patterns of ABC-class genes in H. coronarium flowers, as well as the homolog of PETAL LOSS (HcPTL). Our studies found that stamen/petal identity or stamen fertility in H. coronarium was not necessarily correlated with the differential expression of HcAP3 and HcAG. We also found a novel spatio-temporal expression pattern for HcPTL mRNA, suggesting it may have evolved a lineage-specific role in the morphogenesis of the Hedychium flower. Our study provides a new transcriptome reference and a functional hypothesis regarding the role of a boundary gene in organ fusion that should be further addressed through phylogenetic analyzes of this gene, as well as functional studies.

Hedychium coronarium的花具有高度专门的花器官：萼萼，花瓣状的退化雄蕊和label。这些器官的形成受两个基因类别的控制：花器官身份基因和器官边界基因，它们可以在花发育过程中单独或共同发挥作用。尽管已经在形态学水平上研究了冠状花序的花器官发生，但是仍然不清楚人们对花发育中出现的特定器官形态所涉及的潜在分子机制的了解。在这里，我们使用比较转录组学与实时定量PCR相结合，研究冠状花冠花中ABC类基因的基因表达模式，以及冠状花序的同源性。重大损失（HcPTL）。我们的研究发现，冠状花冠线虫的雄蕊/花瓣身份或雄蕊育性不一定与HcAP3和HcAG的差异表达有关。我们还发现了HcPTL mRNA的新型时空表达模式，表明它可能已经在Hedychium花的形态发生中进化了谱系特异性作用。我们的研究为边界基因在器官融合中的作用提供了新的转录组参考和功能假设，应通过对该基因的系统发育分析以及功能研究进一步解决。