Re: Are genetically modified crops necessary for harsh climates?

Hi Charles,

I would have to say that there is not yet a definitive answer to your question. To make your question a little bit more precise, I will rephrase it as: “Is genetic engineering necessary to develop crops that are productive in harsh climates”

First, I would like to address some terms that are commonly used and commonly misunderstood, and in some cases, are poorly defined.

The term “Genetically modified” is perhaps the least precise. Taking the term literally, there are many ways to genetically modify organisms. Selective breeding, which has been practiced for thousands of years, results in organisms with modified, or changed, genetic content, but, for whatever reason, this is not how the term “genetically modified” is typically used. Random mutagenesis is a more recent technique that is used to produce new characteristics in crop plants. This is performed by exposing plants to some physical or chemical treatment that damages DNA, resulting in mutations. The resulting individuals have surely been modified at the genetic level, but again, this is not what the term “genetically modified” is commonly used.

Currently, the term “genetically modified” is generally used to describe organisms that have been subject to “genetic engineering”, which is a more deliberate modification or addition of specific genes to an organism using modern molecular biology techniques. I will assume that is what you mean by the terms “genetically modified crops” and “gm food”. Genetic engineering usually involves transferring a gene or genes from one species into another species, yielding a “transgenic” organism. For example, a gene from bacteria could be transferred into the genome of a plant.

Of course, “harsh climates” includes covers a broad range of environments, including:

Hot
Cold
Dry
Salty soil
Flooded soil

Traditional breeding programs have had varying degrees of success in developing varieties of plants that are more tolerant of different harsh conditions. The limitation of traditional breeding is that it relies on the genetic variation that is present in a particular species. The long time hope of plant biologists is that transgenic technology would allow scientists to introduce more genetic variation, in the form of foreign genes, into crop plants.

All plants have ways to respond to harsh conditions, and there are various plants that survive particularly harsh conditions. The hope has been that, if we can understand how plants respond to those conditions, and understand how wild plants survive those conditions, we could deliberately modify the genome of a specific crop plant in a way that would allow for greater vigor and productivity under those conditions. For example, if scientists could identify the genes responsible for drought tolerance in some wild desert plant, perhaps they could transfer those genes to a crop plant, making it drought tolerant. As it turns out, the genetic basis for tolerance of environmental stresses (aka “harsh conditions”) is quite complex. As a result, efforts to genetically engineer crop plants to tolerate harsh conditions have progressed slowly. However, transgenic technology remains as a technique that can introduce novel characteristics into plants, and as such, holds the potential to change crop plants in ways that traditional breeding cannot.

My own opinion is that transgenic technology should be considered as one tool in the plant breeder’s toolbox, and that the use of both methods in concert has the greatest potential.

Dr. Alex Brands
Lehigh University