华中农业大学讯（通讯员 廖晓利 王珺 吴智浩）近日，我校丁寄花教授团队联合瑞典农业科学大学Ove Nilsson教授团队在PNAS杂志发表题为“Genetic Control of Seasonal Meristem Arrest in Trees”的研究论文。该研究首次确定杨树AP2-like转录因子在决定林木顶端干细胞活性中的核心作用，揭示了其在进化中的功能重塑：从一年生植物“生命终结开关”到多年生林木“季节调度员”的功能转变。
杨树AP2-like转录因子调控季节性生长的核心功能
杨树携带许多可以相互补偿的AP2-like基因，揭示AP2-like的功能需要付出巨大的技术努力。为了揭示它们的全部功能，研究人员使用CRISPR-Cas9基因编辑技术敲除了不同的基因组合，最终创造了六重突变体，包括其中所有十二个等位基因（六个相关基因各有两个拷贝）被同时失活。通过比较基因组学、遗传学与功能实验相结合的方法，研究团队系统阐释了该基因在多年生林木中的表达模式与调控网络，明确了其在维持顶端分生组织活性、调控季节周期性生长中的核心地位。该工作为明晰多年生植物生存策略演化提供重要遗传基础。
林木季节性生长是林木生存、质量与品质的关键，该研究为林木分子设计育种提供了重要靶点与理论支撑，助力创制具有节律适应性强、生长特性优良的新型林木种质，对应对全球气候变化、推动林业可持续发展具有重要意义。
我校树木分子物候团队博士生王珺、博士后廖晓利、博士生吴智浩、瑞典农业科学大学Shashank Sane博士为论文共同第一作者，丁寄花教授和瑞典农业科学大学Ove Nilsson教授为共同通讯作者。该研究由国家科技部重点研发计划、国家自然科学基金、中央高校基本科研业务费等项目资助。
论文链接：https://www.pnas.org/doi/10.1073/pnas.2505641122
英文摘要：Perennial plants, such as trees native to temperate and boreal regions, exhibit meristems that undergo annual cycles of activity and rest to synchronize their growth cycles with seasonal changes, ensuring survival under harsh winter conditions. The arrest of shoot meristem growth, known as growth cessation, is a critical initial step for trees to enter dormancy. This process is triggered by a combination of endogenous and exogenous signals, yet the molecular mechanisms and signaling pathways underlying growth cessation remain poorly understood. In this study, we demonstrate that Populus orthologs of APETALA2-like transcription factors (AP2Ls), the primary regulators of global proliferative arrest (GPA) in Arabidopsis, play a crucial role in the regulation of seasonal growth cessation in hybrid aspen trees. In particular, AP2Ls act as important activators of the expression of FLOWERING LOCUS T2 (FT2), a key gene for short-day-induced growth cessation. This contrasts with the established role of AP2Ls as repressors of FT in annual plants. Yet, the pathway itself is conserved with the pathway regulating GPA in annual plants, a completely different process during the plant life cycle. Our research highlights both the conserved roles and functional diversities of AP2Ls in a more general balancing of meristem proliferation and arrest in perennial plants, providing insights into the evolutionary adaptation of growth regulation mechanisms across plant species.
审核人：丁寄花
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