Pseudomonas sp. F204 Promoted Tomato Growth and Altered Rhizosphere Bacteria Community

Extracellular DNA (eDNA), as a potential plant autotoxin, can cause soil sickness, negatively affecting plant growth and reducing crop yield. Some microbial taxa can degrade eDNA; however, the effect of these bacteria on plant growth and rhizosphere microbial communities is unknown. In this study, eDNA-degrading bacterial strains were screened from soils, and their eDNA-degrading ability and plant-growth-promoting characteristics were tested in vitro. The effects of the most potent eDNA-degrading strain on tomato plant growth were assessed, and changes in the rhizosphere bacterial community were analyzed using high-throughput amplicon sequencing. Among a total of more than 600 isolated strains, Pseudomonas sp. F204 showed the strongest eDNA-degradation capacity and exhibited phosphate solubilization, siderophore, and indole-3-acetic acid production abilities. Pot experiment showed that inoculation of Pseudomonas sp. F204 significantly altered tomato rhizosphere bacterial community structure and composition, and stimulated the growth of tomato seedlings. Overall, this study shows that eDNA-degrading bacteria can alter rhizosphere bacterial community and promote plant growth, and highlights the important role of soil microbial community in alleviating autotoxicity in continuous cropping systems.