When it becomes too cold or a predator draws near, animals can flee to nicer locales. Plants, on the other hand, do not have this luxury. Instead, they have evolved chemical defences to deter pests and respond to changes in their environment. Dr Ella Katz of the University of California, Davis, is interested in the wide variety of chemical defences found in plants. In a recent study, she and her colleagues show that geography, environment, population history and genetics all combine to produce different chemical defences within the same plant species.
