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Tuesday, December 11, 2012

Science in Action: Part III. Frankenplants

They have been called Monster plants, Frankenseeds or Frankenplants. Scientists have inserted "antifreeze" protein genes from flounder into tomatoes to protect the fruit from frost damage, chicken genes have been inserted into potatoes to increase disease resistance, firefly genes have been injected into corn plants. These are plants created in laboratories that never could have been developed by the traditional means of plant breeding.

Bizarre examples of genetically modified organisms

Plants that have been genetically engineered to resist herbicides and insects, resist freezing temperatures, produce pharmaceutical drugs and to convert nitrogen directly from the soil and developed by large multinational companies at tremendous cost are now being grown in the hopes of much larger profits. Biotechnologies of this type have evolved so quickly that the scientific community has split in the controversy and the rapid advancement of this science has left the general public and many scientists behind in ignorance and Universities scrambling for position.

The last two articles discussed how the disease crown gall was used, in the very early days of genetic engineering, to insert genetic information into plants. This ultimately led to technologies like the “gene gun” and how genes, like the one that produces the toxin from Bacillus thuriengensis (Bt), could be inserted so that crops could be protected from insects.

These two articles made it sound like biotechnology may lead to a scientifically founded Garden of Eden. To be fair, in Part III, a few of the arguments against this technology follows.

Genetic engineering is an imperfect science and not enough is known about what will happen in the long run. Many times researchers who insert genes, creating new organisms, operate with a scatter-gun approach, not knowing where the gene will end up over time or what effects it will have in the long run. Science knows very little about what a gene might trigger or interrupt depending on where it is inserted into the new host plant or animal.

Though often thought of as being precise by laypeople, inserting genes is a rather crude technology, lacking precision and predictability. The "new" gene can end up somewhere or doing something unexpected. For example, when genes for the color red were placed into petunias, this gene not only changed the color of the flower petals but also, unexpectedly, decreased the plant’s fertility and changed the growth of its roots and leaves. Salmon, which were genetically engineered to produce a growth hormone, not only grew bigger than expected and too fast but also turned green. These were unpredictable, scientifically termed pleiotropic, effects.

How do we know that a genetically engineered food plant will not produce new toxins and allergenic substances? How will the nutritional value of genetically modified foods change or will it? What will be the effects on the environment that comes in contact with these plants and on the wildlife in the food chain? Remember DDT? Examples of unexpected results from biotechnology:

·       An attempt to make potato plants resistant to sap-sucking insects has made them more vulnerable to other kinds of insect pests.

·       Crops such as maize and cotton have already been made resistant to chewing insects by adding a gene for Bt. But adding the Bt gene has led to speculation that there will be an increased attack by insects such as leafhoppers and aphids due to an unexpected drop in chemicals that deter their feeding.

·       The stems of a genetically altered, herbicide-resistant soybean were found uncharacteristically to crack open in hot climates.

All these questions are important questions yet they remain unanswered until the biologically altered plant leaves the test tube and enters the real world. The argument is that biotechnology fostered by corporations tends to ignore caution in favor of profits.

Genetically engineered organisms will disrupt our environment. Traditional plant breeding was limited to plants or animals that were compatible biologically which in turn limited the diversity of possible offspring. Breeding through gene-splicing techniques will create life forms that have never before existed, theoretically in billions of different possible combinations which can result in billions of different possible outcomes, some predictable and others not. As these new life forms escape or are introduced into the environment and enter different habitats they may do so with no environmental checks and balances.

We can look at past scenarios where biological organisms were released into new habitats with no checks and balances to see what will happen. While many have adapted without severe problems, a small percentage of them have not. These include the Kudzu vine, gypsy moth, saltcedar, Dutch Elm disease, Chestnut blight, starlings and the Mediterranean fruit fly to name a few. Whenever a genetically engineered organism is released it must be remembered that it may cause a disruption to a complex environment with pre-existing relationships that have developed over long periods of evolutionary history.

This has been characterized sometimes as a type of environmental “pollution”. But because this pollution is a “living pollution” these organisms will be more unpredictable than nonbiological pollutants. Genetically engineered products reproduce. When genetically engineered crops are grown for a specific purpose, they cannot be easily isolated both from spreading into the wild and from cross-pollinating with wild relatives.

It has already been shown that cross-pollination with “normal plants” can take place almost a mile away from the genetically engineered plantings. Three mile buffers are now being recommended in some countries. If we accept the concept that the environments and habitats have their own corrective mechanisms that allow them to “heal”, then radical changes to these environments from genetically modified organisms will require stronger corrective measures if it can be healed at all.

Ordinary pests could become "Super-pests". Much of the current effort in profit-centered, agricultural biotechnology is centered on the creation of herbicide-tolerant, pest-resistant and virus-resistant plants. The idea is to sell farmers patented seeds in the hope of increasing a company's share of both the seed and pesticide markets. The chemical companies hope to convince farmers that the new pest-tolerant crops will allow for a more efficient eradication of pests. In the case of herbicides, farmers will be able to spray at any time during the growing season, killing weeds without killing their crops.

Plants engineered to be pest resistant could become so invasive they are a weed problem themselves, or they could spread their resistance to wild weeds making them more invasive. A growing number of ecologists are concerned with "gene flow" which is the transfer of genes to weeds by way of cross-pollination. Researchers are concerned that manufactured genes for herbicide tolerance, and pest and viral resistance, might escape and create weeds that are resistant to herbicides, pests and viruses.

A Danish research team documented the transfer of a gene from a genetically modified crop to a weed surrounding the crop. This was unexpected among biotechnologists since they had dismissed this possibility even though critics had warned for years prior that it could happen.

Another fear is that insecticide-producing plants might create "super bugs" resistant to the effects of the new pesticide-producing genetic crops and that virus-resistant transgenic crops pose the equally dangerous possibility of creating new viruses that have never before existed in nature.

Putting the crowning touches on ecologists’ fears was the refusal by the insurance companies to insure against catastrophic environmental damage caused by genetically engineered organisms released into the environment.

Regardless of the criticism, bioengineered plants are here to stay. The question will remain how this new technology will be handled responsibly.

This article was previously published by the author in Southwest Trees and Turf

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