解磷真菌可分泌有机酸以螯合土壤中金属离子从而将难溶性磷转化为易于被植物吸收的可溶性磷，对提高磷肥利用效率有重大意义。面向有机酸溶磷机理的研究多以钙磷为研究对象，而铁磷胁迫下解磷真菌特异性分泌有机酸的机制尚不清楚，限制了解磷真菌生物调控途径研究的深入和真菌制剂在含铁土农田中的应用。本项目以预实验筛选得到的溶铁型高效解磷真菌变色栓菌为研究对象，探究解磷真菌溶解铁磷过程中有机酸代谢及动态溶磷动力学规律；模拟铁磷胁迫下解磷真菌生长代谢，阐明解磷真菌代谢活动对有机酸溶磷的协同和拮抗作用机制；利用平板隔离和液体培养法探究铁磷对有机酸代谢的接触诱导激发作用、对解磷真菌的抑制作用和可溶性磷对解磷真菌有机酸代谢的反馈调节作用，揭示铁磷对解磷真菌溶磷过程中的诱导调控和两者间的互作机制。解析铁磷与解磷真菌有机酸代谢互作机制有助于揭示解磷微生物的有机酸溶磷机理，为合理施肥和提高磷元素的利用效率提供科学的理论依据。

The phosphorus solubilizing microorganisms secrete organic acids to chalet metal ions and turn insoluble phosphorus into plant available state, which increases the efficiency of phosphorus fertilizer. Current researches of phosphorus solubilizing mechanisms mainly work with calcium phosphate, however, the reasons why the microbes secrete the specific organic acids for iron phosphate solubilization are unclear. This project will work on the iron-phosphate targeted phosphorus solubilizing fungi (PSF) screened previously. The organic acids metabolization and iron phosphate solubilizing kinetics will be studied. The synergistic and antagonistic effects between the PSF growth and the iron phosphate solubilization of organic acids will be explored by simulating the PSF metabolization process. The inducing effects of iron phosphate on organic acid production as well as the inhibition of iron phosphate on PSF growth will be explored by plate-isolation method. The effects of soluble phosphorus on PSF organic acid production will be studied in liquid culture. This project will reveal a deep view on the interaction mechanisms of iron phosphorus, PSF organic acid metabolization, and provide a theoretical basis for phosphorus fertilizer application and reducing phosphorus run off.