Legumes form symbioses with rhizobia to fix N₂ in root nodules to supplement their nitrogen (N) requirements. Many studies have shown how symbioses affect the shoot, but far less is understood about how they modify root development and root system architecture (RSA). RSA is the distribution of roots in space and over time. RSA reflects host resource allocation into below-ground organs and patterns of host resource foraging underpinning its resource acquisition capacity. Recent studies have revealed a more comprehensive relationship between hosts and symbionts: the latter can affect host resource acquisition for phosphate and iron, and the symbiont’s production of plant growth regulators can enhance host resource flux and abundance. We review the current understanding of the effects of rhizobia–legume symbioses on legume root systems. We focus on resource acquisition and allocation within the host to conceptualize the effect of symbioses on RSA, and highlight opportunities for new directions of research.

中文翻译：

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根瘤菌-豆科植物共生对宿主根系结构的影响。


豆科植物与根瘤菌形成共生，将 N ₂固定在根瘤中，以补充其氮 (N) 需求。许多研究已经表明共生如何影响芽，但对于它们如何改变根发育和根系统结构（RSA）的了解却少之又少。 RSA 是根在空间和时间上的分布。 RSA反映了宿主资源在地下器官的分配以及支撑其资源获取能力的宿主资源觅食模式。最近的研究揭示了宿主与共生体之间更全面的关系：后者可以影响宿主对磷酸盐和铁的资源获取，而共生体产生的植物生长调节剂可以增强宿主资源通量和丰度。我们回顾了目前对根瘤菌-豆科植物共生对豆科植物根系影响的理解。我们专注于宿主内部的资源获取和分配，以概念化共生对 RSA 的影响，并强调新研究方向的机会。