Phosphorus (P) plays an important role in soybean growth and reproduction. Wild soybean (Glycine soja) expressed higher tolerance to P-limited environment compared to cultivated soybeans (Glycine max). In this study, wild and cultivated soybean were used to compare the changes and differences in young and old leaves by ion contents and the kinds, number, and metabolic pathways of small molecule metabolites analysis under low P conditions. Our results showed that under low P conditions, Mg²⁺, Fe³⁺, and SO₄²⁻ increased in young and old leaves of wild soybean; NO₃⁻ increased in young leaves of wild soybean and decreased in old leaves; H₂PO₄⁻ was relatively stable in young leaves of wild soybean. And then, tricarboxylic acid (TCA) metabolism was enhanced and hexose-phosphate metabolism was inhibited in young and old leaves of wild soybean; aspartic acid family amino acids, glutamic acid family amino acids, serine family amino acids, aromatic amino acids metabolisms in young and old leaves of wild soybean were enhanced which contributed to the reuse of amino acids; disaccharides metabolism in young leaves of wild soybean was enhanced. Our experiment indicated that wild soybean could tolerate low P by promoting ion, disaccharides and amino acid metabolites accumulation and reuse in young and old leaves, and enhancing the energy metabolism in young and old leaves, and promoting the decomposition of hexose-phosphate in old leaves for reuse in young leaves. Our results provided a new insight for the cultivation of new soybean varieties with tolerance to P deficiency.

磷（P）在大豆生长和繁殖中起着重要作用。与栽培大豆 ( Glycine max )相比，野生大豆 ( Glycine soja ) 对限磷环境表现出更高的耐受性。本研究利用野生大豆和栽培大豆，比较了低磷条件下小分子代谢物的种类、数量和代谢途径等离子含量的变化和老叶的变化和差异。结果表明，在低磷条件下，野生大豆幼叶和老叶的Mg ²⁺、Fe ³⁺和SO ₄ ^{2- 均}增加；NO ₃ ^-野生大豆幼叶增加，老叶减少；H ₂PO ₄ ^-在野生大豆幼叶中相对稳定。然后，野生大豆幼叶和老叶中三羧酸（TCA）代谢增强，磷酸己糖代谢受到抑制；增强了野生大豆幼叶和老叶的天冬氨酸家族氨基酸、谷氨酸家族氨基酸、丝氨酸家族氨基酸、芳香族氨基酸代谢，促进了氨基酸的再利用；野生大豆幼叶中的双糖代谢增强。我们的实验表明，野生大豆可以通过促进幼叶和老叶中离子、双糖和氨基酸代谢物的积累和再利用，增强幼叶和老叶的能量代谢，促进老叶中磷酸己糖的分解来耐受低磷。在嫩叶中重复使用。