Iturins produced by Bacillus velezensis Jt84 play a key role in the biocontrol of rice blast disease

•Bacillus velezensis Jt84gfp strain was used for colonization in rice leaves.•Bacillus velezensis Jt84 significantly reduced the incidence of rice blast disease at the seedling stage.•Iturins play a key role in the biocontrol of rice blast disease.