BIOTECHNOLOGICAL APPROACHES FOR BIOFORTIFICATION OF VEGETABLE CROPS: FROM NUTRIENT ENHANCEMENT TO PRECISION GENOME EDITING

Abstract

Micronutrient malnutrition, or “hidden hunger,” continues to affect more than two billion people worldwide, with iron, zinc, vitamin A, folate, and iodine deficiencies imposing the greatest public health burden. Vegetables are among the most concentrated dietary sources of vitamins, minerals, and health-promoting phytochemicals, yet their nutritional potential is often eroded by narrow cultivar selection, post-harvest losses, and cooking practices, and is rarely realised at population scale through diet diversification alone. Biofortification the deliberate enrichment of the edible portions of crops with bioavailable nutrients has therefore emerged as a complementary, sustainable strategy to conventional supplementation and industrial fortification. This review synthesises the conventional, agronomic, and biotechnological toolkit available for biofortifying vegetable crops, tracing the field’s progression from soil and foliar nutrient management and marker-assisted breeding through transgenic metabolic engineering to contemporary CRISPR/Cas-based precision genome editing. We examine the molecular mechanisms governing carotenoid, ascorbate, folate, tocopherol, anthocyanin, and mineral accumulation, and we compile documented genome-editing interventions in tomato, potato, carrot, Brassica vegetables, lettuce, pepper, cucumber, and eggplant that have altered nutritional or antinutritional traits. Complementary developments in multi-omics profiling, marker-assisted and genomic selection, tissue culture-based metabolite induction, and nanotechnology-enabled nutrient delivery are discussed alongside the trade-offs, regulatory heterogeneity, and consumer-acceptance barriers that continue to constrain deployment. We argue that the convergence of multiplexed genome editing, base and prime editing, and multi-omics-guided candidate gene discovery is positioning precision breeding to accelerate the second generation of biofortified vegetables, provided that regulatory harmonisation and public engagement keep pace with the underlying science.