Abstract: Poplar is a major afforestation species which is widely planted worldwide. With the continuous expansion of poplar plant areas, the occurrence of poplar canker disease increased rapidly, causing serious damage to the trees. Currently, the major controlling method for poplar canker is chemical agents, but side effects such as environmental pollution and pathogen resistance are becoming more and more serious. There is an urgent need for developing effective non-polluting means to control the canker disease. By using microbiomes as a research tool, beneficial microorganisms that enhance plant disease resistance can be obtained. These antagonistic bacteria can inhibit the growth of canker pathogens without environmental pollution, and have good biological-control potential. This review mainly explores the role and mechanisms of antagonistic bacteria in the control of poplar canker, including inhibiting the growth of pathogenic bacteria through nutrient and water competition, secreting bacteriostatic substances, improving plant disease resistance to resist pathogen infection, and improving the host's own reactive oxygen species tolerance, in order to provide a theoretical basis for the development of efficient and specific bacterial agents, and scientific prevention and control technology.

Key words: Antagonistic microbes, Poplar canker, Biocontrol, Mechanisms