Comparative transcriptomics of two petal variants reveals key functional genes underlying petal shape development in lotus (

Introduction: The lotus ( Methods: This study focused on two variants with distinct petal shapes: the broad petals of Results: It revealed that the broad petal variation of M512 was caused by a reduction in petal length while maintaining width, whereas the narrow petal phenotype of CSFY resulted from a combination of increased length and decreased width. The final petal shapes in both variants were primarily determined by the total number of cells along the petal's longitudinal (length) and transverse (width) directions, rather than by cell size or shape. A total of 59 and 96 candidate genes associated with petal shape development were identified in broad-petaled M512 and narrow-petaled CSFY, respectively. Many of these genes are directly involved in the development of cell wall/membrane and in the synthesis and metabolic pathways of plant hormones such as cytokinins, auxins, jasmonic acid, and brassinosteroids. Discussion: The main framework for petal shape was established during stages D1 and D5. The key genes identified in this study will facilitate the development of artificial techniques for petal shape regulation and serve as a theoretical foundation for molecular-assisted breeding in lotus.