Transcription Factor <i>RhCUC3</i> Regulates Petal Numbers in Rose Flowers

Rose is one of the most popular ornamental plants worldwide. The double-flower trait, referring to flowers with extra petals, has been a key focus in rose breeding history. However, the genetic mechanisms regulating petal number in roses are still not fully understood. Here, we identified the <i&...

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Bibliographic Details
Main Authors: Yan Fang, Zixin Zhao, Yuanji Shen, Zheyuan Ding, Yongyi Cui, Wen Chen
Format: Article
Language:English
Published: MDPI AG 2025-02-01
Series:Horticulturae
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Online Access:https://www.mdpi.com/2311-7524/11/2/170
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Summary:Rose is one of the most popular ornamental plants worldwide. The double-flower trait, referring to flowers with extra petals, has been a key focus in rose breeding history. However, the genetic mechanisms regulating petal number in roses are still not fully understood. Here, we identified the <i>CUP-SHAPED COTYLEDON 3</i> (<i>RhCUC3</i>) gene in the miniature rose (<i>Rosa hybrida</i> ‘Eclair’). The expression of <i>RhCUC3</i> was high during the petal and stamen primordium differentiation stages but declined sharply during pistil primordium development. <i>RhCUC3</i> belongs to the NAM/CUC3 subgroup of NAC transcription factors and is localized in the nucleus. The transcript level of <i>RhCUC3</i> increased significantly with ABA and GA treatments and was inversely down-regulated with MeJA and 6-BA treatments. Silencing <i>RhCUC3</i> using virus-induced gene silencing (VIGS) in rose ‘Eclair’ significantly decreased the number of petaloid stamens and normal petals while slightly increasing the number of stamens. Additionally, the expression of <i>RhAG</i> and <i>RhAGL</i>, two MADS-box genes associated with floral organ identity, was significantly higher in TRV-<i>RhCUC3</i> compared to the TRV control. These findings suggest that <i>RhCUC3</i> enhances stamen petaloidy and petal number, potentially by modulating the expression of <i>RhAG</i> and <i>RhAGL</i>, providing new insights into the function of NAC transcription factors in plants.
ISSN:2311-7524