Transgenic Crops: Advances in Genetic Engineering, Biofortification and Emerging Applications with Associated Biosafety Concerns

Transgenic crops have emerged as a transformative innovation in modern agriculture, offering targeted solutions to challenges related to food security, micronutrient deficiency, biotic and abiotic stresses, and sustainable production systems. Since the advent of recombinant DNA technology in the early 1980s, genetic engineering has enabled the precise introduction of desirable genes across taxonomic boundaries using methods such as biolistic transformation, Agrobacterium-mediated gene transfer, and viral vector systems. This review comprehensively examines the molecular strategies underlying transgenic crop development and highlights their applications in agronomic improvement, including insect resistance, herbicide tolerance, and viral resistance. Particular emphasis is placed on biofortification approaches aimed at enhancing provitamin A, iron, zinc, folate, and vitamin E content through metabolic engineering, nicotianamine synthase overexpression, ferritin integration, and phytate reduction strategies. Beyond agronomic traits, emerging applications such as edible vaccines, plant-based biopharmaceuticals, biodegradable polymer production, and transgrafting technologies are discussed as innovative extensions of transgenic platforms. Despite demonstrated benefits in productivity and nutritional enhancement, concerns regarding biosafety, gene flow, resistance evolution, allergenicity, and public acceptance continue to shape regulatory landscapes worldwide. The review further outlines advancements in cisgenesis, intragenesis, and genome editing as refined alternatives to classical transgenic approaches. Collectively, transgenic technologies represent a pivotal tool for developing climate-resilient, nutrient-enriched, and multifunctional crops, provided that scientific innovation is balanced with rigorous safety assessment and societal engagement.