Cellular dynamics and regulation of cambium stem cells during secondary growth

地球森林中的大多数植物生物量是形成层的产物。形成层是植物茎中的圆柱形分生组织区域，其含有形成层干细胞（CSCs），所述形成层干细胞提供向内产生木质部和向外产生韧皮部的细胞，以使植物体沿着径向轴扩大。这种次生加厚生长通过产生次生脉管系统在生理上支持植物的连续生长，并且通过扩大轴的半径在机械上支持植物的连续生长。尽管其重要性，CSC增殖和分化的调控机制仍然知之甚少。以拟南芥形成层为模型系统，揭示了CSCs在持续次生生长中的调控机制。我将揭示CSC在二次生长过程中的细胞动力学，并以单细胞分辨率表征CSC及其分化后代的转录组，以确定形成层中的新原则和调节因子。CSC系统与其他植物干细胞系统如顶端分生组织干细胞系统在其动力学和双面分化模式上不同。我的工作不仅将加速CSC的研究，而且将为植物干细胞研究的未来研究提供有价值的见解。

Most of the plant biomass in the Earth’s forests is the product of the cambium. As a cylindrical meristematic region in plant stems, the cambium harbours cambium stem cells (CSCs) that provide cells for generating xylem inwards and phloem outwards to enlarge the plant body along the radial axis. This secondary thickening growth supports the continuous growth of plants physiologically by generating secondary vasculature and mechanically by enlarging the radius of the axes. Despite their importance, the regulatory mechanisms of CSC proliferation and differentiation remain poorly understood. Using the Arabidopsis cambium as a model system, I propose to reveal the regulatory mechanisms of CSCs enabling the continuous secondary growth. I will uncover the cellular dynamics of CSCs during secondary growth and characterize the transcriptome of CSCs and their differentiating daughters with single-cell resolution to identify novel principles and regulators in the cambium. The CSC system differs from other plant stem cell systems like the apical meristem stem cell systems in its dynamics and in the bifacial differentiation pattern. My proposed work will not only accelerate CSC research, but will also provide valuable insights for the future studies of plant stem cell research.