GMO Myths and Truths

You can change the meaning of a sentence by changing the sequence of letters in the
sentence, and you can change the “meaning” of a gene or its associated genetic control
elements by changing the sequence of letters within the genetic code of that gene or control
element. Mutations are physical alterations in the sequence of the four letters of the genetic
alphabet within the DNA.
Mutation breeding is the process of exposing plant seeds to mutagens – physical or chemical
agents that damage the DNA, causing mutations. In practice, these agents are either
ionizing radiation (X-rays or gamma rays) or compounds that physically or chemically react
with DNA.
The types of mutations that can be created range from a change in a single genetic letter
(for example, “A” can be replaced with “C”, or “G” with “T”), to the deletion of one or many
letters, to rearrangements of small or large stretches of the DNA sequence.
This process of change in the DNA is known as mutagenesis. Mutagenesis can completely
destroy the function of a gene – “knockout” its function – or it can cause the gene to direct
the cell to produce one or more proteins with altered function. In addition, mutagenesis can
alter the functioning of the genetic control elements associated with a gene or genes and
thus alter the amount, timing, or location of the protein products produced from them. The
resulting plant is called a mutant.
It is a fortuitous and infrequent event when a mutation improves the functioning of an
organism. More often, mutations are damaging or silent (no observable effect). Damage
can range from death of the plant, to minor reductions in productivity or vigour, to changes
in the function or structure of the organism, and even to the quality or safety of the food
derived from the crop plant.
Once plants carrying radiation-induced mutations have been created, they are crossed with
other crop varieties using conventional breeding (the same process is used with GM crop
varieties). However, mutation breeding is not in itself conventional breeding.
Where did radiation-induced mutation breeding come from?
Mutation breeding using radiation started in the 1920s. It became more widely used in the
1950s, after the US atomic bombing of Japan at the end of World War II in 1945. In the
wake of the devastation, there was a desire to find uses for the “peaceful atom” that were
helpful to humanity. Atomic Gardens were set up in the US and Europe, and even in Japan,
with the aim of creating high-yielding and disease-resistant crops. They were laid out in a
circle with a radiation source in the middle that exposed plants and their seeds to radiation.
This caused mutations in the plants, which radiation enthusiasts hoped would be beneficial.
Public relations campaigns euphemistically described the plants as “atom energized”.
However, the results of these projects were poorly documented and do not qualify as
scientific research. It is unclear whether any useful plant varieties emerged from Atomic
Garden projects. 3
Today, radiation-induced mutation breeding is carried out in laboratories. This branch of
GMO Myths and Truths 44