The Role of the γ-Aminobutyric Acid (GABA) in Plant Salt Stress Tolerance

?-Aminobutyric acid (GABA) is a non-protein amino acid that accumulates in many plant species in response to environmental stress. A number of reverse-genetic experiments and omics analyses have revealed positive relationships between GABA levels and tolerance to stresses. Furthermore, the application of exogenous GABA has been demonstrated to effectively reduce ROS levels, enhance membrane stability and modulate phytohormones cross-talk, thus improving tolerance against multiple stresses. However, molecular mechanisms regulating GABA homeostasis and physiological functions in plants remain largely unclear. In this review, we focus on the recent achievements in deciphering the role of genetic manipulations to modulate endogenous GABA levels and the exogenous application of GABA and associated metabolites to improve tolerance to salt stress. Finally, we discuss the role of GABA in the regulation of ion homeostasis in high-salinity conditions. These findings have laid the groundwork for future studies to explore the genetic, physiological, and molecular mechanisms of GABA-mediated improvements in plant productivity under high-salt environmental conditions.

Automated summary

GABA is a non-protein amino acid that accumulates in plants in response to environmental stress. Increasing GABA levels can enhance plant tolerance to stress by reducing ROS levels, enhancing membrane stability, and modulating phytohormones cross-talk. However, the molecular mechanisms of GABA regulation and its physiological functions in plants remain unclear. This review focuses on recent studies that explore the role of genetic manipulation and exogenous application of GABA in improving tolerance to salt stress, as well as the role of GABA in ion homeostasis under high-salinity conditions.