Atmospheric nitrogen (N₂)-fixing legume trees are frequently used for the restoration of depleted, degraded, and contaminated soils. However, biological N₂ fixation (BNF) can also be performed by so-called actinorhizal plants. Actinorhizal plants include a high diversity of woody species and therefore can be applied in a broad spectrum of environments. In contrast to N₂-fixing legumes, the potential of actinorhizal plants for soil restoration remains largely unexplored. In this Opinion, we propose related basic research requirements for the characterization of environmental stress responses that determine the restoration potential of actinorhizal plants for depleted, degraded, and contaminated soils. We identify advantages and unexplored processes of actinorhizal plants and describe a mainly uncharted avenue of future research for this important group of plant species.

固定大气氮（N ₂ ）的豆科植物经常用于修复枯竭、退化和污染的土壤。然而，生物N ₂固定（BNF）也可以通过所谓的放线菌植物进行。放线菌植物包括高度多样性的木本物种，因此可以应用于广泛的环境中。与固定N ₂的豆科植物相比，放线根植物修复土壤的潜力在很大程度上仍未被开发。在本意见中，我们提出了环境胁迫响应特征的相关基础研究要求，以确定放线菌植物对枯竭、退化和污染土壤的恢复潜力。我们确定了放线菌植物的优势和未探索的过程，并描述了这一重要植物物种未来研究的主要未知途径。