Diseases that affect crops in the agroecosystem endanger the safety and security of food supplies worldwide. An efficient and long-lasting strategy for managing plant diseases is to manipulate the target plants' built-in defence mechanisms. The growth along with development of plants mainly depends on the nitrogen. It is one of the most important macronutrients required for the synthesis of amino acids, proteins, nucleic acids, and many other important biomolecules. Besides its role in plant growth and development, nitrogen also plays a crucial role in the defense mechanism against disease in plants. Nitrogen is involved in the synthesis of defense-related compounds such as phytoalexins, pathogenesis-related (PR) proteins, and enzymes. These compounds play a vital role in plant defense against various pathogens. In general, N has positive effects on defence-related enzymes and proteins to influence both local defence and systemic resistance, but negative effects on physical defences and the production of anti-microbial phytoalexins. In this article, we will discuss the role of nitrogen in the defense mechanism against disease in plants.

Keywords : Plant Disease, PR Protein, N, Defense Mechanism.