Glyphosate tolerant genetically modified (GM) maize NK603 was assessed as ‘substantially equivalent’
to its isogenic counterpart by a nutrient composition analysis in order to be granted market approval.
We have applied contemporary in depth molecular profiling methods of NK603 maize kernels (sprayed
or unsprayed with Roundup) and the isogenic corn to reassess its substantial equivalence status.
Proteome profiles of the maize kernels revealed alterations in the levels of enzymes of glycolysis
and TCA cycle pathways, which were reflective of an imbalance in energy metabolism. Changes in
proteins and metabolites of glutathione metabolism were indicative of increased oxidative stress.
The most pronounced metabolome differences between NK603 and its isogenic counterpart consisted
of an increase in polyamines including N-acetyl-cadaverine (2.9-fold), N-acetylputrescine (1.8-fold),
putrescine (2.7-fold) and cadaverine (28-fold), which depending on context can be either protective
or a cause of toxicity. Our molecular profiling results show that NK603 and its isogenic control are not
substantially equivalent.