Placeholder Banner

6 Different Processes Used to Genetically Modify Crops

July 27, 2015
Generations can be defined by the advancements in science and technology. However, communicating the science around these innovations can be one of the biggest challenges. For example, popular culture has taken inspiration from innovations in genetic engineering and created movies like Jurassic World, Xmen and Divergent. The problem is that these stories don’t accurately portray the science of genetic modification and the benefits it can have on society.

In attempt to educate people about genetic modification, Layla Katiraee and Karl Haro Mogel cleverly created an easy-to-read infographic to explain the six most common crop modification techniques:

  1. Cross Breeding: This technique has been used since the 1700s, it’s when you take two sexually compatible crops and cross pollinate them to produce a hybrid. Some examples are the plumcot (plum and apricot), tangelos (tangerine and grapefruit), the limequat (lime and kumquat) and most famously the rabbage (cabbage and radish).

  2. Mutagenesis: Mutations (muta) are genetic changes that can switch, add, or delete nucleotides (those A,T,G and C bases), these genetic changes can sometimes lead to new/enhanced traits which is why plant breeders sometimes induce (genesis) these genetic changes using radiation or chemicals. Hermann Muller, Charlotte Auerbach and J. M. Robson founded this technique in the first half of the 20th century. For example, radiation was used to produce a deeper color in the red grapefruit.

  3. Protoplast Fusion: Sounds scary right? It’s actually when you take two plant cells which have their hard cell walls removed (Protoplasts) and you add a chemical called polyethylene which allow the two cells to stick together. Once they are stuck together basic chemicals are added to help the two cells combine and exchange genetic information to create a hybridized plant cell (fusion). It’s much like cross breeding, except it’s done in a lab.

  4. Polyploidy: We, humans, are diploid animals, which mean we have two sets of homologous chromosomes. Polyploidy have more than one, and the induction of polyploidy is used by plant breeders to control reproduction. Introducing polyploidy by soaking seeds in colchcine can either make sterile crosses fertile, like the Triticale (hybrid of wheat and rye), or sterilizes crops, like watermelon, to make seedless strains.

  5. Genome Editing: This process has the ability to cut, replace or insert genes within the seed cells using “molecular scissors” called nucleases—enzymes which have the ability to loosen, remove and add nucleotides. These nucleases are artificially engineered to accurately place in desired genes, or traits, into the genome of the crop. Herbicide tolerant canola was created using this technique to help famers control weeds.

  6. Transgenisis:  When genes from one crop are incorporated into another crop. Since the genetic code is readable by all living organisms, this means that the genes introduced will code for the same proteins as it did before. There are many ways to introduce these new genes, like using agrobacterium to carry it into the genome, or using electricity. I was even learning how to transform yeast in my biology classes at school.

Crop modification techniquesClick for PDF

Hopefully by understanding the science behind these techniques, you’re able to see past the fearful propaganda against GM foods and understand that genetic modification isn’t science fiction.
Each of these methods has similarities and differences, and some work better for some traits rather than others. Each of them modifies the genetic makeup of the plant in order to combine useful traits together to improve agriculture. However, socially and politically the products of these methods are treated very differently. The fact that the changes that these techniques introduce do not line up with how they are treated when it comes to debates over the regulations for health and environmental safety.  For instance, transgenesis produces far fewer changes and unintended consequences than mutagenesis while mutagenesis is generally accepted and ignored in political discussions.
Layla Katiraee and Karl Haro Mogel