Gamma aminobutyrate: from intellectual curiosity to practical pest control

The authors describe the development of gamma aminobutyrate (GABA) as a potential control agent in plant – invertebrate pest systems. The evidence indicates that GABA accumulation in plants in response to biotic and abiotic stresses is mediated via the activation of glutamate decarboxylase. More applied research, based on the fact that GABA acts as an inhibitory neurotransmitter in invertebrate pests, indicates that ingested GABA disrupts nerve functioning and causes damage to oblique-banded leafroller larvae, and that walking or herbivory by tobacco budworm and oblique-banded leafroller larvae stimulate GABA accumulation in soybean and tobacco, respectively. In addition, elevated levels of endogenous GABA in genetically engineered tobacco deter feeding by tobacco budworm larvae and infestation by the northern root-knot nematode. It is concluded that genetically engineered crop species overexpressing glutamate decarboxylase and having high GABA-producing potential may be an alternative strategy to chemical pesticides for the management of invertebrate pests.