Indirect plant defences have largely been studied within the scope of above-ground interactions. Here we provide novel evidence that root herbivory can induce an above-ground indirect defence. Cotton plants (Gossypium herbaceum) exposed to root-feeding wireworms (Agriotes lineatus) increased their foliar extrafloral nectar production ten-fold in comparison to undamaged control plants. Mechanical root damage also yielded an increase in nectar production. In nature, extrafloral nectar production allows plants to recruit predators, which in turn protect the plant against above-ground insect herbivores. Our results show that root-feeding herbivores may alter such above-ground defensive interactions.
First demonstration that interactions between soil and aboveground ecosystems can be mediated by induced plant secondary metabolites. Applications include induced crop resistance. The experiments were devised by FLW and conducted by Dr. Martijn Bezemer, working as a postdoc with FLW at the Netherlands Institute of Ecology, Heteren, during 2000-2002. RAE_import_type : Journal article RAE_uoa_type : Earth Systems and Environmental Sciences