What is the impact of genetic modification on the elemental composition of plants? This is what North-West University (NWU) PhD student Elvis Moyo investigated through the application of laser-induced breakdown spectroscopy (LIBS) for his study on the elemental composition of organic and genetically modified (GM) plants.

This study was part of his master’s degree in applied radiation at the Centre for Applied Radiation Science and Technology.

Elvis says he used two techniques, LIBS and ICP-MS. “LIBS is a non-destructive elemental analysis technique based on laser ablation and elemental excitation, while ICP-MS is an elemental quantification technique based on high temperature ionization.

“Laser ablation is a powerful approach to chemical analysis because of its versatility,” he explains.

He says the research was driven by the hypothesis that genetic modification, including the change in the genetic make-up of the plant to meet food security demands, leads to a change in the elemental composition of plants.

“Hence, analysing and comparing the elemental composition of organic and GM plants respectively can be a key solution towards solving plant diseases or the adverse environmental effects stemming from genetically modified plants, which can be due to an excess or deficiency of elements,” he says.

There were many techniques available to do the study, but Elvis opted for LIBS because it is non-invasive and permits concurrent multi-elemental examination in a single measurement, with little or no sample preparation.

‘‘By using the LIBS technique, one is able to differentiate the two categories according to the signature of their essential and trace elements and the signature of their geological location,” he adds.

Results from the two techniques showed that the same elements were found in both categories of plants, but in different concentrations. “This means that genetic modification alters the plants’ elemental concentration without necessarily eliminating other essential elements.”

“Therefore, analysing and comparing the elemental composition between organic and genetically modified plants can be the key solution to solve plant-related diseases. It could also provide the answer for the environmental unfriendliness imposed by genetically modified plants, which can be due to the excess, deficiency or change in elemental expression,” concludes Elvis.

Elvis Moyo.