As an important organic acid, α-ketoglutaric acid not only participates in a variety of biochemical processes in plants, but also has significant antioxidant properties, which can enhance the stress resistance of plants. Here are a few key ways that alpha-ketoglutaric acid can help plants improve their stress resistance:

　　1. Scavenging reactive oxygen species

　　Alpha-ketoglutaric acid can effectively remove reactive oxygen species (ROS) in plant cells, such as superoxide anions and hydrogen peroxide. Excessive production of these free radicals under adverse conditions (such as drought, high temperature, low temperature, etc.) will cause damage to plant cell membranes and trigger oxidative stress. The antioxidant properties of alpha-ketoglutaric acid help to reduce this damage and protect the structural integrity of cells.

　　2. Regulate osmotic pressure balance

　　Under stress conditions, alpha-ketoglutaric acid can help plants regulate osmotic pressure balance and maintain water balance by accumulating in cells, thereby reducing cell damage caused by lack of water. This is especially important for plant survival in dry conditions.

　　3. Promote amino acid and protein synthesis

　　Alpha-ketoglutaric acid is an important precursor of amino acid synthesis, which can promote the synthesis of amino acids and proteins. Under stress conditions, these proteins help to maintain normal metabolic activities of plants and improve the adaptability of plants to adversity.

　　4. Promote the synthesis of secondary metabolites

　　Alpha-ketoglutaric acid can also promote the synthesis of secondary metabolites in plants, which play an important role in plant resistance to disease and stress. For example, it can promote the synthesis of phenolic compounds, flavonoids and other antioxidants, and enhance the resistance of plants.

　　5. Example description

　　One study took wheat under drought stress as an example, and found that alpha-ketoglutaric acid can significantly improve the drought resistance of wheat. Under severe stress conditions, after being treated with 5 mmol/L of alpha-ketoglutaric acid for 24 hours, the dry weight of wheat increased by 12.27% compared with the untreated control group, even exceeding the control group under normal moisture conditions. These results indicated that α-ketoglutaric acid could effectively alleviate the inhibition effect of drought on wheat growth.

　　Alpha-ketoglutaric acid enhances plant stress resistance through a variety of mechanisms, including scavenging reactive oxygen species, regulating osmotic pressure balance, promoting amino acid and protein synthesis, and promoting secondary metabolite synthesis. These effects enable plants to better adapt to various adverse conditions, such as drought, high temperature, low temperature, salt and alkali, so as to ensure the continuity and stability of plant growth, and improve crop yield and quality.