Ma Chengdong, Zhou Pengyu, Ma Yufan, Tan Wei, Huang Xiao, Segbo Silas, Iqbal Shahid, Shi Ting, Ni Zhaojun, Gao Zhihong
Laboratory of Fruit Tree Biotechnology, College of Horticulture, Nanjing Agricultural University, No.1 Weigang, Xuanwu District, Nanjing 210095, China.
Horticultural Science Department, North Florida Research and Education Center, University of Florida/IFAS, 155 Research Road, Quincy, FL 32351, USA.
Hortic Res. 2025 Jun 23;12(9):uhaf157. doi: 10.1093/hr/uhaf157. eCollection 2025 Sep.
The photoperiod is essential to flower induction, and the exact timing of the process can be precisely regulated based on the relative duration of light and darkness. However, the mechanisms linking photoperiod and flower induction in woody plants remain largely unexplored. Using RNA-seq, we identified a photoperiod response factor , which is predominantly expressed in early-flowering varieties. Overexpression of in , tobacco, and calli resulted in accelerated flowering. Binding and activation analyses revealed that can be directly suppressed by REVEILLE 1 (RVE1) and REVEILLE 3 (RVE3), implying that plays a role in the photoperiodic signaling pathway. Further studies established that PmNAC32 functions as a positive regulator of () and a negative regulator of (). Interestingly, we identified two homologs of PmNAC32, namely PmNAC29 and PmNAC47. These three proteins can interact with each other and enhance the regulation of and . Although PmNAC29 and PmNAC47 can promote flower induction respectively, neither of them responded to the photoperiod. Thus, our results reveal a novel mechanism by which regulates flower induction in .
光周期对花诱导至关重要，并且该过程的确切时间可以根据光和暗的相对持续时间进行精确调节。然而，木本植物中连接光周期和花诱导的机制在很大程度上仍未被探索。利用RNA测序，我们鉴定出一个光周期响应因子，其主要在早花品种中表达。在杨树、烟草和愈伤组织中过表达该因子导致开花加速。结合和激活分析表明，该因子可被生物钟相关蛋白REVEILLE 1（RVE1）和REVEILLE 3（RVE3）直接抑制，这意味着该因子在光周期信号通路中起作用。进一步研究确定PmNAC32作为杨树中开花促进因子（PuFT）的正调控因子和开花抑制因子（PuTFL1）的负调控因子发挥作用。有趣的是，我们鉴定出PmNAC32的两个同源物，即PmNAC29和PmNAC47。这三种蛋白质可以相互作用并增强对PuFT和PuTFL1的调控。虽然PmNAC29和PmNAC47分别可以促进花诱导，但它们都不响应光周期。因此，我们的结果揭示了一种新的机制，通过该机制PmNAC32调控杨树中的花诱导。
