14 Jul 14

Exploring GM Foods (Part I – A Molecule is Born)

The birth and rebirth of one of the world’s leading germicides, the world’s food problem and more.


A mixture of about 50 parts of glycine, 92 parts of chloromethylphosphonic acid, 150 parts of 50% aqueous sodium hydroxide and 100 parts water was introduced into a suitable reaction vessel and maintained at reflux temperature while an additional 50 parts of 50% aqueous sodium hydroxide was added. The pH of the reaction mixture was maintained between 10 and 12 by the rate of addition of sodium hydroxide. After all of the caustic solution had been added, the reaction mixture was refluxed for an additional 20 hours, cooled to room temperature and filtered. About 160 parts of concentrated hydrochloric acid were then added and the mixture filtered to provide a clear solution which slowly deposited N-phosphonomethylglycine.

Thus begins the story of one of the most controversial molecules invented by man: N-phosphonomethylglycine or Glyphosate as it came to be known . Its discoverer, John Franz – a Monsanto chemist – had begun tinkering with phosphonic acid compounds around the time Armstrong set foot on the moon. This was after Monsanto had witnessed countless failures in trying to come up with an effective herbicide. Then, one fine day, Franz took a giant leap for Monsanto. Glyphosate was born. As it turned out, it was an ordinary molecule, an analogue of the smallest known amino acid glycine. Its power, though, was anything but ordinary – in fact it was spectacular. Glyphosate could effectively kill 76 of the world’s 78 worst weeds. Soon, the world caught on to this magic compound. It was easy to administer and once absorbed could reach most of the weeds’ tissues. Monsanto finally had a money-spinner on its hands – they gave it the name Roundup – and in no time Roundup became the world’s largest selling herbicide, constituting a significant chunk of Monsanto’s earnings.

Much later, Franz – inducted into the hallowed Inventors Hall of Fame in 2007 – would say of his discovery, “I think it has benefited mankind.” One may agree or disagree with Franz’s opinion but what cannot be denied is that Roundup is now used regularly in more than 130 countries with its use set to increase to an astonishing 1.35 million tonnes by 2017. A large part of this is also due to changing agricultural practices, with farmers now inclined to rid their fields of weeds through herbicides rather than tilling. Following the expiry of its patent in 1991, glyphosate is now being manufactured worldwide by hundreds of companies out to make a neat fortune. Predictably, China has quickly become a leader, producing most of the world’s glyphosate.

The world likes glyphosate, and Europe – though it has in place some of the most stringent environmental guidelines – is no exception. Glyphosate accounts for 35% of all pesticides used in Denmark, is sprayed on as much as 40% of German farmland each year, and is the most widely used herbicide in Britain.

Europe might like glyphosate but it is America that loves it. During the two decades following its approval for agricultural use, Roundup was instrumental in revolutionising American farming, bringing in greater yields and more profits. That said, Roundup was just one among many available herbicides – it was only a matter of time before its popularity ebbed and another molecule took its spot. That is until a remarkable feat of genetic engineering allowed glyphosate to once again become a blockbuster in the mechanised world of American agriculture. And that cunning ploy had all to do with the way glyphosate killed weeds.

With the advent of new biochemical and biophysical techniques, scientists were able to study glyphosate’s mode of action in great detail. What they discovered made them draw a collective breath. This tiny molecule, it transpired, attacked the one enzyme that allows the growing plant to make aromatic amino acids through what is known as the shikimate pathway. As luck would have it, mammals don’t possess this enzyme and must acquire the aromatic amino acids like tyrosine, phenylalanine, or tryptophan from their diet.

The stage was set. By 1980, scientists had identified the protein targeted by glyphosate – 5-enolpyruvoylshikimate-3-phosphate synthase, or EPSPS, a key enzyme involved in the synthesis of aromatic amino acids. EPSPS accomplishes the crucial task of joining together two molecules: the EP group from phosphoenol pyruvate (PEP) and shikimate-3-phosphate (SP), resulting in 5-enolpyruvylshikimate-3-phosphate, or EPSP. Glyphosate – a sworn enemy of its doppelgänger EP – is quick to wrest SP away the moment it eyes the latter (called competitive inhibition in scientific parlance). Indeed, the specificity of glyphosate for EPSPS is so exquisite that it doesn’t fit inside any other known plant enzyme. And once it has bound EPSPS, it prevents the biosynthesis of not only the aromatic amino acids but also tetrahydrofolate, ubiquinone, and vitamin K, crucial molecules that make up as much as 35% of plant dry-weight. But what does this quarrel over SP look like – is there a photograph of the crime scene? There soon appeared one – an X-ray structure of the glyphosate-SP complex in stunning atomic detail. It confirmed the long-held view that glyphosate, after it binds to SP, brings about a conformational change in the enzyme EPSPS. EPSPS becomes resigned to its fate, becomes more “stable”.

In 1986, with enough now known about how glyphosate functions, Shah and co-workers did the unthinkable – added a glyphosate-resistant ESPS to a plant chromosome. Their landmark paper, titled: Engineering herbicide tolerance in transgenic plants, and published in the journal Science, opened the floodgates for genetic engineering of glyphosate-tolerant crops. Soon, glyphosate-tolerant soybean entered the market. The EPSPS it carried was from the common soil bacterium, Agrobacterium tumefaciens and extremely resistant to glyphosate, with the result that the soybean expressing this protein was resistant to glyphosate, too. Scientists soon discovered that glyphosate-tolerance is brought about by minute, single amino acid changes in the EPSPS protein sequence. For example, a single change from arginine to alanine in EPSPS can prevent both SP and glyphosate from binding EPSPS, a remarkable occurrence.

Monsanto called the crop Roundup-ready, meaning that such type of genetically engineered crops could be sown without tilling, without the ubiquitous channels – thus saving on a large percentage of usable farmland – and sprinkled freely with glyphosate to kill the undesirable weeds.

There was no looking back. In 2012, roughly 30 mha (million hectares) of American farmland was used for growing soybean out of which, according to the 2013 data available at the United States Department of Agriculture, USDA, more than 90% was of the Roundup-ready variety. The figures for glyphosate-tolerant cotton and corn were 80% and 75% respectively.

Another 35 mha were used for growing non-soybean Roundup-ready crops. In 2011, 59% of all GM crops cultivated worldwide were herbicide-resistant. The Center for Environmental Risk Assessment carries an extensive database on all the Roundup-ready crops there are in the market – cotton, maize, alfalfa, canola, sorghum, and soybean to name a few.

Genetic modification of crops, though, had its detractors and in the case of glyphosate – and later glyphosate-resistant crops – they came by the thousands, led predominantly by activists like the philosopher Vandana Shiva, founder of the NGO Navdanya.

“The continuing wars in Afghanistan, Iraq and onwards,” cried Dr Shiva, “are not only about blood for oil. As they unfold, we will see that they are about blood for food, blood for genes and biodiversity and blood for water. The war mentality underlying military-industrial agriculture is evident from the names of Monsanto’s herbicides – Round-Up”.

Blood, toil, tears, and sweat. The gavel had descended. Soon, based on single, untested, or irreproducible scientific reports, the cries for banning glyphosate and glyphosate-resistant crops became shriller. It did not matter that GM crops were grown around the world by 17 million farmers on over 170 mha of land, it did not matter that such crops went through an achingly stringent regulatory mechanism, or that none other than the WHO had declared GM foods to be safe – none of it mattered one iota. It was a case of seeing what one believes and the opponents of GM food saw glyphosate as the first tomato to squash in their quest for non-GM world domination.

Theorists need to be right every time, conspiracy theorists just once.

In Part II of this series we shall look dispassionately at the scientific facts regarding glyphosate and glyphosate-resistant GM crops. We need to. If one is to feed nine billion people – the projected population of the world in 2050 – the food production has to increase by a whopping 70% over the current levels. Farmlands are not Nariman Points, to be reclaimed from the sea as and when one pleases. Food productivity has to increase through means other than expansion of cultivation areas. “We could,” says UK’s chief scientist Prof Beddington, “cut down tropical rain forests and plant crops on the savannahs to grow more food, but that would leave us even more vulnerable to the impact of global warming and climate change.”

Where are we going to get all that food from? Organic Farming – the cynosure of every environmentalist’s eye (and dealt with in detail in Part V) – is not a viable option. Dacha gardens can’t feed the world, only the politburo. There are no easy solutions for “Project 2050”. That said, the decision to ban glyphosate once and for all cannot be faulted if it is based on hard, irrefutable, reproducible, scientific evidence. After all, glyphosate wouldn’t be the first molecule to be outlawed – Endosulfan, DDT, and Thalidomide stand as grim reminders of the havoc innocent-looking molecules can wreak on humanity and the environment. That Endosulfan use is still allowed in India – it was banned in the USA in 2002 – speaks volumes for our concern for the lives of our people.

Glyphosate, on the other hand, has not been banned anywhere in the world, including of course the USA that is its largest consumer. American and European lives are as much at risk as Indian lives. We are all in it together. Before we commit to killing glyphosate and glyphosate-resistant crops it is imperative that we analyse the scientific evidence before us. With our conscience thus clear, we are at full liberty to consign Franz’s baby to the bin. But our collective decision has to be devoid of an agenda. After all, we have the bathwater to consider.


This article first appeared in newslaundry on Jul. 14, 2014.

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