Phosphorus (P) is an essential macronutrient for optimum productivity of several crops including soybean, but it is largely limited in most arable lands. The persistent depletion of phosphate rocks is a major constraint for plant growth and development. Improved P efficiency (PE, uptake and use efficiency) drives an enhanced biological nitrogen fixation in soybean, which could consequently lead to an increased grain and biomass production. Thus, to mitigate P limitation in soybean production, a wide range of genetic approaches have been deployed. These approaches have unravelled the morphological, genetic, phytohormonal and metabolic mechanisms involved in soybean adaptations to P-deficient conditions. Most of the approaches are targeted at root modifications due to the importance of roots in the mediation of early responses to P-deficient conditions. PE among soybean genotypes in P-deficient conditions is mostly dependent on the root plasticity, development of shallow root architecture, symbiosis with arbuscular mycorrhizal fungi and exudation of phosphatases and organic acid anions. Genetic manipulation of soybean has revealed a number of important genes (GmPAPs, GmPTs, GmPLDZ2, GmIPS1 and GmExPB2), transcription factors (C2H2 zinc finger protein, WRKY and MYB) and quantitative trait loci (q14-2 and q19-2) modulating P mobilisation, uptake and utilization under P limiting conditions. Through the modification of root traits, the hormonal (biosynthesis, transport and secretion of ethylene, auxin and jasmonic acid) and metabolic (phenylpropanoid biosynthesis and phenylalanine metabolisms) pathways also modulate PE in soybean. Recent advances in genetic manipulations of root traits offer promising ways for enhancing soybean production, particularly in a P limiting environment.

磷（P）是包括大豆在内的多种作物的最佳生产力所必需的大量营养素，但在大多数耕地中磷素受到很大限制。磷矿的持续消耗是植物生长发育的主要障碍。磷的有效利用率（PE，吸收和利用效率）提高了大豆中的生物固氮能力，因此可能导致谷物和生物量生产的增加。因此，为了减轻大豆生产中的磷限制，已经采用了广泛的遗传方法。这些方法揭示了大豆适应缺磷条件的形态，遗传，植物激素和代谢机制。由于根在调解对缺磷症早期反应中的重要性，因此大多数方法都针对根的修饰。缺磷条件下大豆基因型中的PE主要取决于根的可塑性，浅根结构的发展，与丛枝菌根真菌的共生以及磷酸酶和有机酸阴离子的渗出。大豆的遗传操作揭示了许多重要基因（GmPAPs，GmPTs，GmPLDZ2，GmIPS1和GmExPB2），转录因子（C2H2锌指蛋白，WRKY和MYB）和定量性状位点（q14-2和q19-2）调节P在磷限制条件下动员，吸收和利用。通过改变根部性状（乙烯的生物合成，运输和分泌，生长素和茉莉酸的代谢途径（苯丙氨酸类生物合成和苯丙氨酸代谢）途径也可以调节大豆中的PE。根部性状的遗传操纵的最新进展为提高大豆产量提供了有希望的方法，特别是在磷限制环境中。