The effects of GABA in plants

Abstract

Υ-aminobutyric acid (GABA) is a non-protein amino acid in a wide range of organisms. In plants, GABA is proposed to take multiple functions under non-stressed and stressed conditions. It is a key metabolite for primary and secondary pathways being an important intermediate of nitrogen metabolism and amino acid biosynthesis. In addition, the GABA metabolism through the GABA shunt provides a source for carbon skeletons and energy for down-stream biosynthetic pathways. GABA is also involved in signaling or regulatory mechanisms. It indirectly affects plant growth and development throughout the whole crop cycle and it accumulates rapidly in response to abiotic stresses. It has been shown to contribute to responses to biotic stresses through multiple mechanisms. An overactivation of the GABA shunt can help to restrict the spread of necrotrophic fungi like Botrytis. The activity of GABA against insects may be based either on a direct inhibitory effect or on an induction of down-stream defense reactions or on a combination of both mechanisms. The dual function of GABA as a metabolite and as a component of signaling pathways is a combination enabling plants to cope with different conditions. Exogenously applied GABA triggers similar effects than the intrinsic molecule and may, therefore, offer the potential to improve the overall vigor of plants.

Keywords

• γ-aminobutyric acid
• gaba
• plant growth
• morphological responses
• physiological responses
• biotic stress
• abiotic stress
• mode of action
• signaling
• stress tolerance