Fusarium fungi cause major crop diseases by using a protein called Fg12 that kills helpful bacteria in plant roots, making it easier for the fungus to infect crops. Scientists discovered that a compound called GMP blocks Fg12’s harmful activity and restores beneficial bacteria, reducing disease symptoms in soybeans and alfalfa by 47-75%. This discovery offers a new chemical strategy to protect crops from fungal infections by disarming this key fungal weapon.