The combined effect of Diversispora versiformis and sodium bentonite contributes on the colonization of Phragmites in cadmium-contaminated soil

ABSTR A C T To promote the colonization of Phragmites in Cd polluted, nutrient deprived and structural damaged soil, the combined remediation using chemical and microbial modifiers were carried out in potting experiments. The co-application of Diversispora versiformis and sodium bentonite significantly improved the soil structure and phos-phorus utilization of the plant, while decreasing the content of cadmium bound by diethylenetriaminepenta-acetic acid by 77.72%. As a result, the Phragmites height, tillers, and photosynthetic capacity were increased by 71.60%, 38.37%, and 17.54%, respectively. Further analysis suggested the co-application increased the abun-dance of phosphorus-releasing microbial communities like Pseudomonas sp. and Gemmatimonadetes. Results of rhizosphere metabolites also proved that the signal molecule of lysophosphatidylcholine regulated the phos-phorus fixation and utilization by the plant. This work finds composite modifiers are effective in the colonization of Phragmites in Cd contaminated soil by decreasing the bioavailable Cd, increasing the abundance of functional microbial communities and regulating the phosphorus fixation.

Automated summary

This study conducted a potting experiment to promote the colonization of Phragmites in Cd polluted, nutrient deprived, and structurally damaged soil using chemical and microbial modifiers. The co-application of Diversispora versiformis and sodium bentonite significantly improved the soil structure and phosphorus utilization of the plant, while reducing the content of cadmium bound by diethylenetriaminepenta-acetic acid. The results showed increased Phragmites height, tillers, and photosynthetic capacity, along with increased abundance of phosphorus-releasing microbial communities and regulation of phosphorus fixation by the plant.