Abstract: The recent advances of pathogen-plant interactions to form galls are reviewed, which focuses on pathogenesis and influencing factors of gall formation of bacteria, fungi, protozoa, insects and nematodes. The disturbance of the phytohormonal balance and the acquisition of meristematic characteristics by differentiated cells are shared causes of gall formation in host plants. Some pathogens manipulate host plant development by secreting effector proteins, benefiting themselves at the expense of the plant growth and reproduction, which results in the formation of galls. Further research fields are suggested.

Key words: plant gall, pathogen, phytohormone, effector proteins