γ-Aminobutyric Acid (GABA) in Agricultural Production

     Synthesis of GABA，γ-Aminobutyric Acid

There are three main methods for synthesizing GABA: phytoaccumulation, microbial fermentation, and chemical synthesis.

Phytoaccumulation utilizes the stress metabolism of plant tissues to enrich GABA, but this method is not suitable for large-scale production.

Microbial fermentation utilizes glutamate (GAA) or monosodium glutamate (MSG) in certain microorganisms, which is then decarboxylated and converted into GABA by glutamate decarboxylase (GAD). This method has advantages such as environmental friendliness, simple equipment, low cost, and a variety of readily available production strains, making it suitable for large-scale industrial production.

     Effects of GABA Application on Plants under Abiotic Stress

Resistance to Low Temperature Stress

Low temperatures increase seed germination time, reduce seedling survival rate and vitality, thus limiting plant absorption and nutrient transport; low temperatures also affect plant photosynthesis, impacting seedling health and ultimately limiting crop yield. Under low-temperature stress, γ-aminobutyric acid (GABA) enhances the low-temperature tolerance of crops by increasing the activity of superoxide dismutase (SOD) and peroxidase (POD) within the plant, protecting tissues and organs, and mitigating the damage caused by low temperatures.

Resistance to Waterlogging Stress Approximately 10 million hectares of crops worldwide are severely affected by floods each year. In major wheat-producing areas such as the middle and lower reaches of the Yangtze River and North China, flood damage ultimately leads to yield reduction. GABA regulates the chlorophyll system during plant photosynthesis, increasing the activity of antioxidant enzymes, thereby reducing the growth-limiting phenomena caused by waterlogging stress and enhancing the waterlogging tolerance of wheat.

Resistance to Salt Stress

Soil salinization is widespread globally. In my country, the area of saline-alkali land is nearly 100 million hectares, with a potential saline-alkali land area of 17.33 million hectares. Plants growing in saline-alkali soils suffer from ion toxicity, osmotic stress, and oxidative stress, causing physiological dysfunction and hindering their growth. Studies have shown that foliar spraying of exogenous γ-aminobutyric acid (GABA) during the tillering and booting stages can increase the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in functional leaves of rice under salt stress, while reducing malondialdehyde (MDA) content. Spraying during the tillering stage is more effective than during the booting stage. Exogenous γ-aminobutyric acid (GABA) can increase the activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), thereby alleviating the damage of salt stress to maize seedlings.

Drought Stress Resistance Drought is one of the major abiotic stresses limiting crop growth and yield. Under drought stress, the photosynthetic capacity of plant leaves decreases, and photosynthetic products are reduced, thus altering the sugar metabolism level within the plant. Studies have shown that exogenous GABA under drought stress can significantly increase rice grain yield and endogenous GABA content.

     Conclusion

Gamma-aminobutyric acid (GABA) is a biostimulant that regulates plant growth. It is environmentally friendly and can regulate normal plant growth and development while mitigating the effects of abiotic stress on plant growth. When low concentrations of GABA are applied exogenously, plant resistance to stress is significantly improved, and the quality and yield of fruits are also significantly increased, making it an invaluable agricultural input.

GABA regulates and induces growth within plants; in simple terms, it tells crops when to flower, when to fruit, and when to feed under stress, thus stimulating plant growth.

     As a fertilizer synergist, GABA has the following significant advantages:

GABA is highly soluble in water, chemically stable, and has a wide range of compatibility with acids and alkalis (stable at pH 3-11). It has excellent compatibility with various media, making it ideal for fertilizer addition and suitable for sprinkler and drip irrigation.

Convenient addition: It can be mixed or sprayed. It is easy to process and produce, has good storage properties, is convenient to transport, and is flexible and convenient to use.