Sugar metabolism in plants is a complex network of interconnected pathways that regulate the production, conversion, storage, and transport of carbohydrates, which serve as the primary source of energy for plant growth and development. The key processes in sugar metabolism include photosynthesis, the process by which plants convert light energy into chemical energy, producing glucose and other sugars. Glycolysis is the breakdown of glucose into pyruvate, producing ATP (adenosine triphosphate) as an energy source for cellular processes. The conversion of glucose into starch for storage in plant tissues and the subsequent breakdown of starch into sugar when energy is required. Sucrose metabolism conversion of glucose into sucrose, the primary transport sugar in plants, which is used to distribute energy to various tissues. Each of these pathways plays a vital role in plant energy management. However, under abiotic stress conditions, these processes can become compromised, leading to reduced energy availability and growth. Therefore, understanding the regulation of sugar metabolism under stress is critical for improving crop performance and resilience. One of the key functions of melatonin in plant metabolism is its regulation of photosynthesis, which directly affects sugar production. Photosynthesis is essential for converting light energy into chemical energy stored in the form of sugars, and any impairment in this process can lead to reduced sugar accumulation and energy deficit in plants. Starch is synthesized in chloroplasts during periods of high photosynthetic activity and stored in vacuoles or amyloplasts for later use. Melatonin serves as a key regulator of starch metabolism, dynamically modulating both starch biosynthesis and degradation to maintain energy homeostasis in plants under changing climatic conditions.