All moral rights asserted. Recolouring or alteration of the image is prohibited without permission. Coloured scanning electron micrograph (SEM) of a cross-section through a coral berry, or Christmas berry, (Ardisia crenata) leaf. Within the leaf are symbiotic Phyllobacterium myrsinacearum bacteria (red.) The bacteria produce an insecticide (FR900359) that makes the plant very resistant to insect damage. FR900359 is being investigated as a potential drug and has been shown to be effective against asthma and certain types of cancer, including choroidal melanoma, in cell and mouse models. Magnification: x1000 when printed at 15 centimetres wide.