Lycopene in tomatoes: genetic regulation, agronomic practices, and environmental influence

Lycopene is one of the key carotenoids in tomatoes (Lycopersicon esculentum Mill.). It is known for its strong antioxidant activity and its role in preventing cardiovascular diseases, cancer, and other chronic conditions. A complex interplay of genetic factors, agronomic practices, and environmental conditions determines its accumulation in tomato fruits. Breeding for high-lycopene tomato varieties is actively advancing through traditional breeding methods and modern molecular markers, which facilitate the identification of promising genotypes and accelerate the breeding process. Beyond genetic traits, external factors significantly impact lycopene synthesis. Temperature regimes, solar radiation levels, photoperiod, and temperature fluctuations on the fruit surface can all influence its accumulation. Agronomic practices, such as growth regulators, organic amendments, and potassium fertilizers, also contribute to increased lycopene content. Potassium enhances carbon transport into the fruits, while organic fertilizers stimulate the enzymatic activity of the carotenoid biosynthesis pathway. Growth regulators can activate gene expression related to lycopene accumulation, offering opportunities for targeted control of its levels. This review uniquely integrates insights from molecular genetics, environmental factors, and agronomic strategies to comprehensively understand lycopene biosynthesis in tomatoes. Systematically connecting molecular mechanisms with practical cultivation approaches addresses a significant gap in the existing literature. Additionally, the ripening stage and storage conditions further affect lycopene content. Thus, an integrated approach- combining molecular marker-assisted breeding, optimized agronomic techniques, and environmental factor management- can significantly enhance lycopene concentration in tomatoes, improving their nutritional value and functional properties. The findings presented offer actionable guidance for future breeding programs and cultivation practices to produce functionally enriched tomato varieties for the health-oriented food market. Keywords: lycopene, tomato, genetic factors, environmental factors, potassium fertilizers, organic fertilizers