Study found Spodoptera frugiperda transfers Bt protein to offspring

 

The Spodoptera frugiperda (Common name: Fall armyworm) can transfer Cry1F proteins - present in transgenic Bacillus thuringiensis (Bt) maize - to its descendants, according to the US scientific journal PLOS One, which may indicate new ways to understand the rapid selection of resistance to genetically modified technologies.

 

According to the Brazilian Agricultural Research Corporation (Embrapa), this means that even before caterpillars hatch, the embryos may have already been exposed to the protein, if the previous generation fed on Bt maize. This protein is toxic to the insect. However, as it is present since the egg stage, it can increase the chances of selecting resistant individuals.

 

"We found that exposure of the main corn pest to one of the Bt proteins already begins in the embryo, which may contribute to resistance selection pressure. In another study, published in 2016 in the European journal Entomologia Experimentalis et Applicata, we showed that, in four generations of laboratory selection, it is possible to select caterpillars that are resistant to this same protein," said researcher Simone Martins Mendes, from the field of Entomology of Embrapa Milho and Sorgo (MG).

 

"In fact, we have followed the speed of selection of the resistance of this species of pest to Bt proteins expressed in transgenic maize under tropical growing conditions. We have already understood that many factors contribute to this situation," noted Mendes.

 

The article, published in PLOS One, is not the first scientific paper to show the process of transmitting Bt protein to insect eggs, in general. Researcher Debora Pires Paula of Embrapa Genetic Resources and Biotechnology (DF), previously detected the Cry1Ac protein in the eggs of another lepidopteran, the insect Chlosyne lacinia, popularly known as the sunflower caterpillar, after the consumption of the protein by the parents, and also on eggs of the predatory ladybird Harmonia axyridis. "However, Spodoptera frugiperda is the main target species of Bt technology in maize, which has shown resistance to the technology for populations collected in 2012," said Paula.