The morphogenesis of plant organs and tissues has fascinated scientists for centuries. However, it remains a challenge to quantitatively decipher the biomechanical mechanisms underlying the morphological evolutions of growing plants. In this study, we investigate the formation, optimization, and evolution mechanisms of plant roots through biomechanical morphogenesis. A transdisciplinary computational framework is established based on the adaptive design domain topology optimization method. Two typical kinds of root systems are studied for illustration, including the taproot and the fibrous systems. The effects of coupled biomechanical and environmental factors on the growth and form of the root systems are revealed. It is found that the morphological evolutions of both systems tend to maximize the transport efficiency of water and nutrients. Lateral roots are constantly generated, forming a hierarchically branched layout. The thickness and concentration of roots depend on the growth history, while the growth directions of root caps are regulated by geotropism, hydrotropism, and growth inertia. These results are consistent with experimental observations. This work not only helps understand the topological formation of root systems, but also provides a quantitative tool for exploring the structure–property–function interrelations of living systems.

几个世纪以来，植物器官和组织的形态发生一直让科学家着迷。然而，定量破译生长植物形态演化背后的生物力学机制仍然是一个挑战。在这项研究中，我们通过生物力学形态发生研究植物根系的形成、优化和进化机制。基于自适应设计域拓扑优化方法建立了跨学科计算框架。为了说明，研究了两种典型的根系，包括主根和纤维系统。揭示了耦合生物力学和环境因素对根系生长和形态的影响。发现这两个系统的形态演化都倾向于最大化水和养分的运输效率。侧根不断产生，形成层次分枝的布局。根系的粗细和浓度取决于生长史，而根冠的生长方向受向地性、向水性和生长惯性的调节。这些结果与实验观察结果一致。这项工作不仅有助于理解根系的拓扑结构，还为探索生命系统的结构-性质-功能相互关系提供了定量工具。