As a central metabolic hub in the Tricarboxylic Acid (TCA) cycle, α-Ketoglutarate (AKG) serves as both a high-efficiency nutrient enhancer and a critical signaling molecule, orchestrating plant defense mechanisms against biotic and abiotic stresses.

• Enhancement of Abiotic Stress Tolerance: AKG significantly bolsters plant resilience under extreme conditions. Exogenous application improves photosynthetic performance and maintains osmotic balance under salinity stress. It also enhances antioxidant enzyme activity to mitigate damage from heat, drought, and heavy metal toxicity by scavenging reactive oxygen species (ROS).
• Nitrogen Metabolism & Ammonia Detoxification: AKG acts as a vital “ammonia scavenger,” converting excess ammonium ions into amino acids (e.g., glutamate) to prevent ammonia toxicity. This optimizes the carbon-nitrogen (C/N) balance, ensuring a stable energy allocation between growth and defense.
• Signaling for Induced Resistance: Functioning within the Systemic Acquired Resistance (SAR) framework, AKG acts as a co-substrate for epigenetic modifications, regulating defense-related gene expression. It synergizes with the Salicylic Acid (SA) pathway to defend against viral, fungal, and bacterial pathogens.
• Yield Improvement & Anti-Senescence: Beyond protection, AKG accelerates growth rates and delays physiological senescence in leaves, maintaining photosynthetic activity for longer durations, which leads to superior crop yield and quality.