Abstract In this study, the root exudates of wetland plants, Pistia stratiotes, black algae, and Cyperus alternifolius, exposed to six phosphorus concentration gradients (0, 0.2, 1, 5, 10, and 20 mg/L) were characterized. The experimental seedlings were cultivated in Hoagland solutions, which were then extracted, decompressed, and concentrated with CH2Cl2; subsequently, a gas chromatography-mass spectrometry (GC-MS) analysis was performed to study the root exudates effects under different phosphorus concentrations. Results showed the existence of several organic compounds, such as alkanes, esters, alcohols, amines, benzene, and acids (phthalic acid, cycloheptasiloxane, benzoic acid, and cyclopentasiloxane) in the root exudates of the wetland plants. The relative contents of phthalate, benzene dicarboxylic acid, and cyclohexasiloxane in the root exudates first increased, and then decreased, with the change in phosphorus concentration. The relative contents of three compounds in Pistia were the highest at 1 mg/L of phosphorus, and the lowest relative contents of phthalic acid and benzene dicarboxylic acid were observed at 20 mg/L of phosphorus. However, the relative content of cyclohexasiloxane was the lowest in the absence of P stress. In black algae, the relative contents of the three compounds were 36.66, 16.24, and 14.61%, respectively. The relative content of cyclohexasiloxane in the black algae first decreased and then increased, with its lowest relative content occurring at 5 mg/L of phosphorus and the highest at 10 mg/L of phosphorus. In Cyperus alternifolius, the highest relative concentrations of the four compounds: phthalic acid, dimethyl phthalate, octadecane, and diphenyl sulfone in Cyperus were observed at 5 mg/L phosphorus and the lowest at 10 mg/L phosphorus.

中文翻译：

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磷胁迫下高原湖滨湿地典型植物根系分泌物释放系统特征

摘要 在这项研究中，湿地植物、Pistia striotes、黑藻和香附子的根系分泌物在暴露于六个磷浓度梯度（0、0.2、1、5、10 和 20 mg/L）时进行了表征。实验幼苗在Hoagland溶液中培养，然后用CH2Cl2提取、减压和浓缩；随后，进行了气相色谱-质谱 (GC-MS) 分析以研究不同磷浓度下根系分泌物的影响。结果表明，湿地植物的根系分泌物中存在多种有机化合物，如烷烃、酯、醇、胺、苯和酸（邻苯二甲酸、环庚硅氧烷、苯甲酸和环戊硅氧烷）。邻苯二甲酸酯、苯二甲酸的相对含量，根系分泌物中环己硅氧烷和环己硅氧烷随着磷浓度的变化先增加后减少。Pistia 中三种化合物的相对含量在 1 mg/L 磷时最高，邻苯二甲酸和苯二羧酸的相对含量在 20 mg/L 磷时最低。然而，在没有 P 应力的情况下，环己硅氧烷的相对含量最低。在黑藻中，三种化合物的相对含量分别为36.66、16.24和14.61%。黑藻中环己硅氧烷的相对含量先降低后升高，磷含量为5mg/L时最低，磷含量为10mg/L时最高。在香附中，四种化合物的相对浓度最高：邻苯二甲酸、