Genetic Engineering of Transgenic Crops

Abstract

Crop genetic engineering has moved well beyond conventional breeding. Researchers now routinely rewrite plant genomes with nucleotide precision, though the underlying biology still resists easy transfer. This review traces how the tools work, where they have succeeded, and where they fall short. A particular focus is the tension between Agrobacterium-mediated delivery and host defense—plants recognize the pathogen through pattern-triggered immunity (PTI), and resistant accessions may mount effector-triggered immunity (ETI), either response capable of aborting transformation. We also contrast the error-prone non-homologous end joining (NHEJ) pathway with template-dependent homology-directed repair (HDR), which remains inefficient in most species.The field has produced scattered but tangible outcomes: CLE promoter editing raises maize yields; base editing yields herbicide-resistant oilseed rape; HDR-derived rice tolerates glyphosate; and metabolic engineering pushes vitamin C higher in tomatoes. Looking ahead, speed breeding merged with precise editing, multiplex engineering, and AI-guided design could push agriculture toward greater sustainability. These advances suggest genetic engineering is becoming indispensable—for food security and for reducing environmental harm.