During this season, once every 4 weeks, I pick one of the 13 most popular episodes from the first two years and post the original interview. These extended editions contain a couple of parts that didn’t make it into the final cut and give an insight into the underlying conversation.Supporters on Patreon have immediate access to these versions, btw. If you are one of them, thank you very much! If not, think about it!

This time I present to you the full conversation to 11: Genetically Modified Crops and the European Union – with Hélène Pidon

Plant geneticists are not happy with the European judgment on gene editing

Dr. Hélène Pidon is a postdoctoral researcher at the Leibniz Institute of Plant Genetics and Crop Plant Research. She searches for genes that give plants resistance to diseases. She wants to use these genes to fortify cultivated Barley against these diseases, and thus reduce the number of pesticides used to grow the plant. When the European Court of Justice ruled on the status of crops modified with gene-editing methods like CRISPR, Hélène contacted me to talk with me about GMO crops.

Crops have been genetically modified for millennia

I was curious about the origins of agriculture and how simple artificial selection of nice-looking plants affected their genomes. For Millennia, farmers would choose a particularly good looking plant to sow its seeds in the next season. Unknowingly, they had a major impact on the whole genome of domesticated plants. For example, the size of the wheat genome tripled – a rather drastic modification. Plant scientists often view the cultivated plants as completely new species that can’t reproduce with their wild counterparts. Domesticated crops like these would not be able to survive in the wild and need constant attendance.

Industrialized Agriculture

With the population boom at the end of the 19th century, farmers needed to outsource their breeding efforts. Companies stepped in producing fertilizers, and pesticides, and also new breeding procedures. Now, specialized breeders would search for plants with valuable traits. These plants would then cross with the currently used crop plant in order to create a new variety with the new trait. However, if you breed your ‘elite’ plant with another plant, the offspring also inherits many unwanted traits. In order to get back to a plant that has all the traits of the current elite crop, and the additional new one, the plants need to be backcrossed with the elite variant many times. This is a very slow and tedious process.

Mutagenesis

To speed things up, breeders figured that it would be better to increase the variability in the offspring of the elite crop. This way they could simply select an elite crop with the new randomly added trait. To do so, breeders use radiation or chemicals to induce a mutation rate that is higher than under natural conditions. This method has been very successful. Today, every major crop has undergone mutagenesis at some point.

Transgenesis and Gene Editing

Today, the latest discoveries in genetics and developments of genetic methods allow identifying the genes underlying the beneficial traits breeders want to add to their crops. With transgenesis, scientists have first become able to introduce complete genes into a genome. The source of this gene is irrelevant. So-called ‘BT crops’ for example, are transgenic plants that received a bacterial gene that makes them resistant to certain insects.