Team:Goettingen/Background
Team Göttingen
iGEM 2018
Glyphosate on my plate?
| E-mail: | igem2018@gwdg.de |
|---|---|
| Adress: | c/o iGEM 2018 |
| Department of General Microbiology | |
| Grisebachstraße 8 | |
| 37077 Göttingen | |
| Germany |
We are especially grateful to our numerous sponsors on gofundme, who supported our project and made it possible.
Every public donor, who helped us to achieve our goals got a special place on our bacterial wall of fame and a handdrawn microbe to show our appreciation. A link to that wall can be found here:
Background
Glyphosate (N-(phosphonomethyl)glycine) was first synthesized by the chemist Dr. Henri Martin in 1950, while working for the Swiss pharmaceutical company Cilag, which was founded in 1936 in Schaffhausen. About 20 years later, the American chemist Dr. John E. Franz who was working for the company Monsanto found out that glyphosate specifically inhibits the 5-enolpyruvyl-shikimate-3-phosphate (EPSP) synthase in plants, fungi, bacteria and archaea (Figure 1) (1). The EPSP synthase generates the precursor for the de novo synthesis of aromatic amino acids tryptophan, tyrosine and phenylalanine. Therefore, inhibition of the EPSP synthase by glyphosate results in the depletion of the cellular levels of aromatic amino acids and death of the organism that is treated with the weedkiller (Figure 1).
Structural comparison of glyphosate and glutamate.
Logo of the Roundup products.
The herbicidal properties of glyphosate were first discovered in 1970 by Dr. John E. Franz, a chemist working for Monsanto. It was patented and introduced to the market as active component in the developed “Roundup®” products in 1974. Glyphosate is a so-called “total-herbicide”, being effective against every kind of plant through the inhibition of the Shikimate pathway. Monsanto sells genetically modified seeds together with the Roundup products to use the full potential of glyphosate. The usage rate of Glyphosate has been ever increasing since its release and is still increasing up to this day, making it the most used herbicide in the USA.
Glyphosate usage over the last two decades. The increase can be described with a linear growing curve.
How does Glyphosate work?
Glyphosate targets the EPSP Synthase in the Shikimate pathway of plants and bacteria. This pathway is used to form essential aromatic amino acids, like Tyrosin, Phenylalanine and Tryptophane, which serve as building blocks for proteins and play a crucial role in metabolism. Amino acids are building blocks for proteins in every organism and thus have to be acquired through nutrition or generated by the organism themselves.
Fully functional Shikimate pathway. The enzyme EPSP-synthase is needed
in order to form the three essential aromatic amino acids Phenylalanine,
Tryptophane and Tyrosine.
Glyphosates ability to inhibit this pathway is the reason why it also classifies as antibiotic, as bacteria are also not able to synthesize the essential amino acids anymore and pass away.
Shikimate pathway interrupted through Glyphosate. Through inhibition
of the EPSP Synthase with Glyphosate the amino acids can’t be generated
anymore.