Jin Weichan, Gong Feifei, Zhang Yuanfei, Wang Rui, Liu Huwei, Wei Yinghao, Tang Kaiyang, Jiang Yunhe, Gao Junping, Sun Xiaoming
Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture, College of Horticulture, China Agricultural University, Beijing 100193, China.
J Exp Bot. 2025 Jan 10;76(2):381-392. doi: 10.1093/jxb/erae331.
Petal size, a crucial trait in the economically important ornamental rose (Rosa hybrida), is synergistically regulated by cell division and cell expansion. Cell division primarily occurs during the early development of petals. However, the molecular mechanism underlying the regulation of petal size is far from clear. In this study, we isolated the transcription factor gene RhSCL28, which is highly expressed at the early stage of rose petal development and is induced by cytokinin. Silencing RhSCL28 resulted in a reduced final petal size and reduced cell number in rose petals. Further analysis showed that RhSCL28 participates in the regulation of cell division by positively regulating the expression of the cyclin genes RhCYCA1;1 and RhCYCB1;2. To explore the potential mechanism for cytokinin-mediated regulation of RhSCL28 expression, we investigated the cytokinin response factor RhRR1 and determined that it positively regulates RhSCL28 expression. Like RhSCL28, silencing RhRR1 also resulted in smaller petals by decreasing cell number. Taken together, these results reveal that the RhRR1-RhSCL28 module positively regulates petal size by promoting cell division in rose.
花瓣大小是经济上重要的观赏玫瑰（Rosa hybrida）的一个关键性状，它受细胞分裂和细胞扩张的协同调控。细胞分裂主要发生在花瓣发育早期。然而，调控花瓣大小的分子机制仍远未明确。在本研究中，我们分离出转录因子基因RhSCL28，它在玫瑰花瓣发育早期高度表达且受细胞分裂素诱导。沉默RhSCL28导致玫瑰花瓣最终大小减小且细胞数量减少。进一步分析表明，RhSCL28通过正向调控细胞周期蛋白基因RhCYCA1;1和RhCYCB1;2的表达参与细胞分裂的调控。为探究细胞分裂素介导的RhSCL28表达调控的潜在机制，我们研究了细胞分裂素响应因子RhRR1，并确定它正向调控RhSCL28的表达。与RhSCL28一样，沉默RhRR1也会通过减少细胞数量导致花瓣变小。综上所述，这些结果表明RhRR1-RhSCL28模块通过促进玫瑰细胞分裂正向调控花瓣大小。
