State Key Laboratory of Efficient Production of Forest Resources, National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, PR China.
J Exp Bot. 2024 Oct 30;75(20):6462-6475. doi: 10.1093/jxb/erae329.
The optimal timing of the transition from vegetative growth to reproductive growth is critical for plant reproductive success, and the underlying regulatory mechanisms have been well studied in angiosperm model species, but relatively little in gymnosperms. DAL1, a MADS domain transcription factor (TF) that shows a conserved age-related expression profile in conifers, may be an age timer. However, how DAL1 mediates the onset of reproductive growth remains poorly understood. Here, we showed that PtDAL1 directly regulates PtDAL10 transcription by binding to its promoter region in vitro. Both in vitro and in Nicotiana benthamiana PtDAL1 forms ternary complexes with PtDAL10 and PtMADS11, two potential candidate regulators of the vegetative to reproductive transition in Chinese pine (Pinus tabuliformis). In new shoots PtDAL10 was progressively induced with age and was also expressed in male and female cones. Overexpression of PtDAL10 rescued the flowering of ft-10 and soc1-1-2 mutants in Arabidopsis. We provide insights into the molecular components associated with PtDAL1, which integrates the vegetative to reproductive phase transition into age-mediated progressive development of the whole plant in conifers.
从营养生长向生殖生长的最佳转变时机对植物的生殖成功至关重要，调控机制在被子植物模式物种中已有深入研究，但在裸子植物中相对较少。DAL1 是一种 MADS 结构域转录因子（TF），在松柏类植物中表现出保守的与年龄相关的表达模式，可能是一个年龄定时器。然而，DAL1 如何介导生殖生长的开始仍然知之甚少。在这里，我们表明 PtDAL1 通过与体外其启动子区域结合，直接调节 PtDAL10 的转录。PtDAL1 在体外和烟草原生质体中与 PtDAL10 和 PtMADS11 形成三元复合物，PtDAL10 和 PtMADS11 是中国松（Pinus tabuliformis）营养生长向生殖生长转变的两个潜在候选调控因子。在新梢中，PtDAL10 随年龄逐渐诱导，并在雄球果和雌球果中表达。在拟南芥中过表达 PtDAL10 挽救了 ft-10 和 soc1-1-2 突变体的开花。我们深入了解了与 PtDAL1 相关的分子成分，它将营养生长向生殖生长的转变整合到了裸子植物中整个植物的年龄介导的渐进发育中。
