Glutamic Acid: A Key Player in Stress-Induced Metabolism

Glutamic acid (Glu) plays a basic and complex function in plant physiology as a central molecule of nitrogen (N) assimilation, amino acid biosynthesis, redox regulation, and stress response. Moreover, Glu is actively engaged in adapting plants to abiotic stress components such as drought, salinity, temperature, and heavy metals via antioxidant functions, reactive oxygen species (ROS) detoxification, and metabolic signaling. In addition, Glu was reported to be a key component in plant response to biotic stress. This chapter aims to describe the Glu biosynthesis pathways and highlight its function as a primary precursor molecule in the plant cell. Specific focus is laid on recent literature regarding exogenously applied Glu and its potential to enhance plant tolerance against environmental stress and the underlying mechanisms of its functions.