Gamma Aminobutyric Acid (γ-GABA)
γ-Aminobutyric Acid (GABA) is a four-carbon non-protein amino acid ubiquitous in organisms, and it is a zwitterion containing amino and carboxyl groups.
γ-GABA can provide nutrients for plants, regulate plant growth and development, induce ethylene production, regulate cell fluid concentration in plants, and participate in many stress-resistant responses, such as resistance to salt stress, high-temperature stress, and low-temperature stress and resistance to drought stress
Adding and spraying γ-GABA can effectively reduce the nitrate content in plants, accelerate the development process, increase the activity of nitrate reductase, accelerate the consumption of soluble sugar, promote protein synthesis, and then improve crop yield and quality. GABA combined with chemical fertilizer application can achieve the effect of reducing fertilizer usage and efficiency enhancement.
Promote Crop Growth and Absorption of Key Nutrients
1. Promote the absorption of mineral elements: Studies have shown that exogenous GABA treatment significantly improves the absorption of K+, Ca2+ and Mg2+ by cucumber roots. Exogenous GABA treatment reduced the uptake of Na+ in the aboveground parts of crops, thereby increasing the ratio of K+/Na+. Exogenous GABA affects the selectivity of plants to absorb mineral elements, increases the absorption rate of large, medium and trace elements, and thus promotes plant growth.
2. Regulating the balance of carbon and nitrogen nutrition: GABA can serve as a temporary nitrogen pool during nitrogen metabolism in higher plants. As a temporary nitrogen source, GABA is directly absorbed and utilized by plants, and connects the two major metabolic pathways of carbon and nitrogen in plants.
Effects of γ-Aminobutyric Acid on Plants Under Adversity Stress
1. Resistance to Low-temperature Stress
Under low temperature stress, γ-aminobutyric acid can protect tissues and organs by increasing the activity of superoxide dismutase (SOD) and peroxidase (POD) in crops and reduce the damage of low temperature to plants, which can improve the low-temperature tolerance of crops.
Exogenous application of γ-aminobutyric acid can accelerate the degradation of energy substances stored in rapeseed leaves, thereby reducing the inhibitory effect of low temperature on rapeseed germination. γ-aminobutyric acid can also promote the accumulation of proline in rape leaves, reduce the water loss in rape leaves, increase the activities of superoxide dismutase (SOD) and peroxidase (POD), and reduce the and lipid peroxidation, increase the expression of cold resistance genes, and simultaneously increase the low-temperature resistance of rapeseed leaves.
2. Resistance to Waterlogging Stress
Exogenous application of 50 mg/L GABA can increase wheat plant height by 28%, total root length by 40%, and maintain high chlorophyll content. γ-aminobutyric acid can increase the activity of antioxidant enzymes by regulating the chlorophyll system during plant photosynthesis, thereby reducing the phenomenon of limiting plant growth caused by waterlogging stress and enhancing the waterlogging tolerance of wheat.
3. Resistance to Salt Stress
Under salt stress, exogenous γ-aminobutyric acid can increase the root surface area, root length, root tip volume and root dry matter mass of maize seedlings. Soluble protein content, root activity, and endogenous GABA content all increased significantly, and root electrical conductivity decreased significantly.
Exogenous γ-aminobutyric acid can significantly increase the activity of peroxidase (POD) and superoxide dismutase (SOD) in the root system, reduce the degree of oxidative damage of the root system, increase the vitality of the root system, and maintain the integrity of the cell membrane.
Thereby increasing the absorption and transportation of nutrients by the root system and improving the growth of the root system.
4. Resistance to Drought Stress
Drought stress affected the rice yield, and after adding exogenous γ-aminobutyric acid, the rice yield reached a normal level, and finally alleviated the impact of drought stress on rice. Application of different concentrations of GABA can significantly increase rice grain yield and endogenous GABA content.
According to our research, γ-aminobutyric acid significantly reduces the malondialdehyde content and cell membrane permeability of wheat seedling leaves, and alleviates the damage to wheat leaf cells.
At the same time, the use of γ-aminobutyric acid can effectively increase the content of soluble sugar, thereby enhancing the ability of wheat to absorb water in the soil, and reducing the impact of drought stress on physiological metabolism.
γ-aminobutyric acid (GABA) can not only regulate the normal growth and development of plants but also alleviate the impact of adversity stress on plant growth in adversity. Spraying γ-aminobutyric acid can significantly improve the stress resistance of plants, and the quality and yield of plant fruits will also be significantly improved.