Researchers tested five types of beneficial fungi from the Beauveria genus to see if they could help tomato plants grow better and resist gray mold disease. They found that all five species could live inside tomato plants and help them grow taller. Most importantly, the fungus Beauveria brongniartii completely protected plants from gray mold infection. By examining which genes were activated in the plants, scientists discovered that these fungi boost the plant’s natural defense systems while also improving photosynthesis.