γ-Aminobutyrate (GABA) Regulated Plant Defense: Mechanisms and Opportunities

Abstract

Global climate change and associated adverse abiotic and biotic stress conditions affect plant growth and development, and agricultural sustainability in general. Abiotic and biotic stresses reduce respiration and associated energy generation in mitochondria, resulting in the elevated production of reactive oxygen species (ROS), which are employed to transmit cellular signaling information in response to the changing conditions. Excessive ROS accumulation can contribute to cell damage and death. Production of the non-protein amino acid γ-aminobutyrate (GABA) is also stimulated, resulting in partial restoration of respiratory processes and energy production. Accumulated GABA can bind directly to the aluminum-activated malate transporter and the guard cell outward rectifying K+ channel, thereby improving drought and hypoxia tolerance, respectively. Genetic manipulation of GABA metabolism and receptors, respectively, reveal positive relationships between GABA levels and abiotic/biotic stress tolerance, and between malate efflux from the root and heavy metal tolerance. The application of exogenous GABA is associated with lower ROS levels, enhanced membrane stability, changes in the levels of non-enzymatic and enzymatic antioxidants, and crosstalk among phytohormones. Exogenous GABA may be an effective and sustainable tolerance strategy against multiple stresses under field conditions.

Genome-Wide Association Study Reveals Marker Trait Associations (MTA) for Waterlogging-Triggered Adventitious Roots and Aerenchyma Formation in Barley

“…Potassium also plays an important role as a determinant of cell fate, with cytosolic K + acting as a trigger of programed cell death under a range of biotic and abiotic stress conditions, and the plant’s ability to take up K + is significantly reduced under O 2 - deficient conditions [ 25 ]. Under waterlogging conditions, the metabolism of gamma aminobutyric acid (GABA) can bind directly to the guard cell outward rectifying K + channels, thereby improving hypoxia tolerance [ 25 , 65 ]. Potassium transporter family genes ( HORVU4Hr1G079150 , 11 mem) and ( HORVU7Hr1G107400 , 32 mem) are positioned within 1 Mb from MTA.WL.RCA.4H and MTA.WL.AR.7H , respectively.…”

Response of Transgenic Potato Plants Expressing Heterologous Genes of ∆9- or ∆12-Acyl-lipid Desaturases to Phytophthora infestans Infection

“…An important feature for the future of plants is their ability to adapt to environmental conditions and the effects of various abiotic and biotic factors, including infection with pathogens [ 1 ]. The adaptation is accompanied by corresponding changes in their metabolism, including those caused by an increase in the number of reactive oxygen species (ROS) [ 2 , 3 , 4 ]. The antioxidant system, comprising mani-fold high- and low-molecular-weight compounds, is involved in the maintenance of ROS balance [ 5 , 6 ].…”

Comparative Transcriptome Analysis of Onion in Response to Infection by Alternaria porri (Ellis) Cifferi

“…This suggests that CYP85A1 might play a role in defense response against pathogen. GABA accumulation after abiotic or biotic stress is reported in several plants ( Rashmi et al, 2018 ), and it might help in enhancing host immunity against fungal pathogens by modulating oxidative enzymes ( Shelp et al, 2021 ). GABA transporter 1 ( GAT1 ) involved in GABA influx into the cell ( Batushansky et al, 2015 ).…”