2. Dr. Michal Gruntman

Plants can respond to heterogeneity in belowground resources by selectively proliferating their roots within nutrient-rich patches. However, an unexplored hypothesis is that such root foraging could be induced by environmental stressors, such as herbivory, which might increase the demand for particular resources, such as those required for herbivore defense. This study examined the way simulated herbivory affects root foraging for cadmium in the metal-hyperaccumulating plant Arabidopsis halleri, which uses this heavy metal as herbivore defense. Simulated herbivory elicited enhanced allocation of roots to cadmium-rich patches, and this response was exhibited particularly by plants from non-metalliferous origin, which have lower metal tolerance. These results provide first support for the idea that root foraging can be induced not only by resource availability but also by environmental changes, such as the presence of herbivores.