Phytate utilization of maize mediated by different nitrogen forms in a plant–arbuscular mycorrhizal fungus–phosphate-solubilizing bacterium system

[摘要] A pot experiment was conducted to investigate the organic phosphorus (P) (phytate) utilization of Zea mays L. with different nitrogen (N) forms (NH 4 + and NO 3 − ) when both arbuscular mycorrhizal (AM) fungus ( Funelliformis mosseae ) and phosphate-solubilizing bacterium (PSB, Pseudomonas alcaligenes ) are present. The soil was supplied with either KNO 3 or (NH 4 ) 2 SO 4 (200 mg kg −1 N) with or without phytin (75 mg P kg −1 ). Results showed that the application of NH 4 + to the soil in a plant–AM fungus–PSB system decreased rhizosphere pH and increased phosphatase activity. It also enhanced the mineralization rate of phytin, which resulted in the release of more inorganic P. The application of NO 3 − promoted mycorrhizal colonization and hyphal length density in the soil. The inorganic P in the hyphosphere decreased, but more P was transferred to the plant through the mycorrhizal hyphae. Hence, in addition, the application of the two different N forms did not significantly alter the content of plant P. The plant supplied with different N fertilizers acquired P through different mechanisms associated with other microbes. NH 4 + application promoted phytin mineralization by decreasing soil pH, whereas NO 3 − application increased inorganic P uptake by strengthening the mycorrhizal pathway.

[学科分类] 纳米科学和纳米技术

[关键词] Funelliformis mosseae;Pseudomonas alcaligenes M20;organic P;ammonium;nitrate;phosphatase activity