Ye Zha-Long, Liao Tang-Quan, Wang Yue, Sun Sheng-Ying, Bai Shu-Nong, Sun Xiao-Mei, Li Wanfeng
State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the National Forestry and Grassland Administration Research Institute of Forestry, Chinese Academy of Forestry Beijing People's Republic of China.
State-Owned Dagujia Forestry Farm in Qingyuan Man Autonomous County Liaoning People's Republic of China.
Plant Direct. 2025 Jul 21;9(7):e70089. doi: 10.1002/pld3.70089. eCollection 2025 Jul.
In angiosperms, such as , silique removal can reverse developmental arrest and reactivate inflorescence meristems, illustrating that post-fertilization growth cessation is a plastic process rather than terminal differentiation. However, it remains unclear whether a similar growth arrest plasticity occurs in conifers, where mature seed cones typically undergo terminal differentiation as determinate structures. In this study, we analyzed the proliferated seed cones of , which exhibited vegetative shoots sprouting from their central axes. We collected and examined both the proliferated and normal seed cones from a second-generation seed orchard. The proliferated seed cones were longer, produced more seeds, had a smaller seed scale spacing, and displayed enhanced secondary growth compared to normal seed cones. Our analysis suggested that the proliferated seed cones underwent a transition from reproductive to vegetative growth after seed production, indicating that proliferative arrest in these cones can be disrupted. Based on structural and developmental comparisons with , the proliferated seed cones exhibit unexpected plasticity: their growth arrest is reversible rather than terminal, similar to silique-removal-induced meristem reactivation in . This suggests that conifer cones retain the ability for delayed differentiation, not only offering new insights into conifer development but also a potential conifer model for studying reproductive-to-vegetative phase transition.
在被子植物中，比如 ，去除角果可以逆转发育停滞并重新激活花序分生组织，这表明受精后生长停止是一个可塑性过程而非终端分化。然而，针叶树中是否发生类似的生长停滞可塑性仍不清楚，在针叶树中，成熟的种球通常作为确定结构经历终端分化。在本研究中，我们分析了 的增殖种球，其从中心轴上长出营养枝。我们从第二代种子园中收集并检查了增殖种球和正常种球。与正常种球相比，增殖种球更长，产生的种子更多，种鳞间距更小，并且次生生长增强。我们的分析表明，增殖种球在种子产生后从生殖生长转变为营养生长，这表明这些种球中的增殖停滞可以被打破。基于与 的结构和发育比较，增殖种球表现出意想不到的可塑性：它们的生长停滞是可逆的而非终端性的，类似于被子植物中去除角果诱导的分生组织重新激活。这表明针叶树种球保留了延迟分化的能力，不仅为针叶树发育提供了新见解，也为研究生殖到营养阶段转变提供了一个潜在的针叶树模型。
