Genetically Modified Crops

About this topic

GM crops have genes from other organisms inserted to give useful traits: Bt maize makes a protein toxic to pests, herbicide-tolerant soy survives weedkillers, and Golden Rice makes beta-carotene to prevent vitamin A deficiency. Genes are transferred with vectors like Agrobacterium or gene guns.

The process is: identify the useful gene, cut it out with restriction enzymes, insert it into a vector such as a plasmid, transfer it into plant cells, and grow the cells into whole plants with tissue culture. Marker genes help select cells that took up the gene. Unlike traditional breeding, which takes many generations, genetic modification can add a specific gene quickly, even from another species.

Benefits include higher yields, less pesticide use, drought tolerance and improved nutrition. Concerns include gene flow to wild relatives, harm to non-target insects, pests evolving resistance, corporate control of seeds and unknown long-term effects. Many regulators have found approved GM foods safe to eat, though debate continues.

A common misconception is that eating GM food changes your own genes; digestion breaks down DNA like any other. Another is that all GM crops are the same; each has to be assessed separately.