Role of Gamma-Aminobutyric Acid in Plant Defense Response

Abstract

Gamma-aminobutyric acid (GABA) is a four-carbon non-protein amino acid that acts as a defense substance and a signaling molecule in various physiological processes, and which helps plants respond to biotic and abiotic stresses. This review focuses on the role of GABA’s synthetic and metabolic pathways in regulating primary plant metabolism, redistributing carbon and nitrogen resources, reducing the accumulation of reactive oxygen species, and improving plants’ tolerance of oxidative stress. This review also highlights the way in which GABA maintains intracellular pH homeostasis by acting as a buffer and activating H+-ATPase. In addition, calcium signals participate in the accumulation process of GABA under stress. Moreover, GABA also transmits calcium signals through receptors to trigger downstream signaling cascades. In conclusion, understanding the role of GABA in this defense response provides a theoretical basis for applying GABA in agriculture and forestry and feasible coping strategies for plants in complex and changeable environments.

Exogenous γ-Aminobutyric Acid Can Improve Seed Germination and Seedling Growth of Two Cotton Cultivars under Salt Stress

“…Among these substances, γ-aminobutyric acid (GABA) emerges as an important active substance with the potential to improve plant resistance to non-biological stress. GABA, known for its environmentally friendly characteristics, actively participates in various physiological activities of plants, encompassing growth, development, signal transduction, and stress response [ 10 , 11 , 12 ]. There is substantial evidence indicating that exogenous GABA can improve seed germination, plant growth and development, and enhance plant tolerance to non-biological stress, such as salt, drought, low temperature, hypoxia, and heavy metals [ 9 , 10 , 11 , 12 , 13 ].…”

“…GABA, known for its environmentally friendly characteristics, actively participates in various physiological activities of plants, encompassing growth, development, signal transduction, and stress response [ 10 , 11 , 12 ]. There is substantial evidence indicating that exogenous GABA can improve seed germination, plant growth and development, and enhance plant tolerance to non-biological stress, such as salt, drought, low temperature, hypoxia, and heavy metals [ 9 , 10 , 11 , 12 , 13 ]. Additionally, GABA contributes to increased nutrient absorption and utilization efficiency by plants, such as nitrogen [ 9 , 10 , 14 , 15 ], phosphorus [ 16 ], potassium [ 17 ], and calcium [ 11 , 12 , 17 ].…”

“…There is substantial evidence indicating that exogenous GABA can improve seed germination, plant growth and development, and enhance plant tolerance to non-biological stress, such as salt, drought, low temperature, hypoxia, and heavy metals [ 9 , 10 , 11 , 12 , 13 ]. Additionally, GABA contributes to increased nutrient absorption and utilization efficiency by plants, such as nitrogen [ 9 , 10 , 14 , 15 ], phosphorus [ 16 ], potassium [ 17 ], and calcium [ 11 , 12 , 17 ]. Exogenous GABA also improves plant growth and alleviates the adverse effects of stress by enhancing antioxidant defense mechanisms [ 10 , 11 , 14 , 15 ].…”

“…Additionally, GABA contributes to increased nutrient absorption and utilization efficiency by plants, such as nitrogen [ 9 , 10 , 14 , 15 ], phosphorus [ 16 ], potassium [ 17 ], and calcium [ 11 , 12 , 17 ]. Exogenous GABA also improves plant growth and alleviates the adverse effects of stress by enhancing antioxidant defense mechanisms [ 10 , 11 , 14 , 15 ]. Exogenous GABA induces an increase in the GABA content in plants [ 9 , 13 ], upregulates the tricarboxylic acid cycle to generate more energy, and plays a critical role in maintaining the carbon–nitrogen balance of plants [ 9 , 11 , 16 ].…”

“…Exogenous GABA also improves plant growth and alleviates the adverse effects of stress by enhancing antioxidant defense mechanisms [ 10 , 11 , 14 , 15 ]. Exogenous GABA induces an increase in the GABA content in plants [ 9 , 13 ], upregulates the tricarboxylic acid cycle to generate more energy, and plays a critical role in maintaining the carbon–nitrogen balance of plants [ 9 , 11 , 16 ]. Especially under salt stress, the accumulation of GABA can activate H + -ATPase, maintaining intracellular pH balance, thereby improving plant salt tolerance [ 11 , 13 ].…”