Yang Xiong, Zhao Tianyun, Rao Pian, Yang Ning, Li Guolei, Jia Liming, An Xinmin, Chen Zhong
State Key Laboratory for Efficient Production of Forest Resources, Key Laboratory of Silviculture and Conservation of the Ministry of Education, National Energy R&D Center for Non-food Biomass, Engineering Research Center for Carbon Sequestration and Sink Enhancement by Forestry and Grass of the Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China.
National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China.
Int J Biol Macromol. 2023 Aug 15;246:125633. doi: 10.1016/j.ijbiomac.2023.125633. Epub 2023 Jul 3.
Poplar is an important tree species for ecological protection, wood production, bioenergy and urban greening; it has been widely planted worldwide. However, the catkin fibers produced by female poplars can cause environmental pollution and safety hazards during spring. This study focused on Populus tomentosa, and revealed the sucrose metabolism regulatory mechanism of catkin fibers development from morphological, physiological and molecular aspects. Paraffin section suggested that poplar catkin fibers were not seed hairs and produced from the epidermal cells of funicle and placenta. Sucrose degradation via invertase and sucrose synthase played the dominant role during poplar catkin fibers development. The expression patterns revealed that sucrose metabolism-related genes played important roles during catkin fibers development. Y1H analysis indicated that there was a potential interaction between sucrose synthase 2 (PtoSUS2)/vacuolar invertase 3 (PtoVIN3) and trichome-regulating MYB transcription factors in poplar. Finally, the two key genes, PtoSUS2 and PtoVIN3, had roles in Arabidopsis trichome density, indicating that sucrose metabolism is important in poplar catkin fibers development. This study is not only helpful for clarifying the mechanism of sucrose regulation during trichome development in perennial woody plants, but also establishes a foundation to solve poplar catkin fibers pollution through genetic engineering methods.
杨树是生态保护、木材生产、生物能源和城市绿化的重要树种；已在全球广泛种植。然而，雌杨树产生的柳絮纤维在春季会造成环境污染和安全隐患。本研究以毛白杨为对象，从形态、生理和分子层面揭示了柳絮纤维发育的蔗糖代谢调控机制。石蜡切片表明，杨树柳絮纤维并非种毛，而是由珠柄和胎座的表皮细胞产生。在杨树柳絮纤维发育过程中，通过转化酶和蔗糖合酶进行的蔗糖降解起主导作用。表达模式显示，蔗糖代谢相关基因在柳絮纤维发育过程中发挥重要作用。酵母单杂交分析表明，杨树中蔗糖合酶2（PtoSUS2）/液泡转化酶3（PtoVIN3）与调控毛状体的MYB转录因子之间存在潜在相互作用。最后，两个关键基因PtoSUS2和PtoVIN3对拟南芥毛状体密度有影响，表明蔗糖代谢在杨树柳絮纤维发育中至关重要。本研究不仅有助于阐明多年生木本植物毛状体发育过程中蔗糖调控的机制，也为通过基因工程方法解决杨树柳絮纤维污染奠定了基础。
