IF WE ARE TO BELIEVE the advertisements and the bold promises of the biotech industry, world hunger will soon be a problem of the past. There will be no further threat to the environment, wildlife or biodiversity through modern agriculture, which depends so heavily on chemicals. Genetic engineering is the way forward. The few mishaps here and there will soon be sorted out. The unpredictability of Nature will be brought under control. Through genetic engineering, food will be better and safer than it ever has been. Plants are already grown that are made to be tolerant to herbicides (weed-killers) or resistant to insects and other pests. Other plants are being developed for resistance to fungal attack or to viruses.

And isn't it a great advance to have fruits that will not rot nor bruise nor ripen before told to do so;  to produce vaccines in bananas and high concentrations of Vitamin A in rice and in rape seed? We can even use crop plants as factories by manipulating their genes so that they produce inedible chemicals and proteins and fibres for industrial purposes. Giant salmon are now grown so fast you can almost watch. Over-sized bulls produce more lean meat than anyone could have dreamed of. What is wrong with envisioning future plants and animals as tailor-made commodities. It seems that the only constraints on the possibilities of biotechnology are the boundaries of our imagination.

Even if all of these dreams were actually achievable and safe, society would have to question the ethics, the political implications, the monopolies created, the patenting of life, the socio-economic effects, the costs to the environment the impact on the Third World and on biodiversity. Or we could simply ask, “What is wrong wirth food and nature as we know it?” The question we must surely ask is, are these technologies really safe.  What are the dangers of geentic engineering itself?  What are the associated hazards and risks?  Do genetic scientists really know what they are doing?
 

HAEMOPHILIA IS THE result of a failure of the gene for the bloodclotting protein (Factor V111) to work properly. The obvious solution is to replace the defective gene with an intact one. But our skills in genetic engineering do not allow such a precise "cut and paste job" among tens of thousands of genes. The best we can do at present is to add a functional gene without removing the bad one. This creates new problems. Where to place the new gene? On which chromosome? At which location? Next to which other gene? Will the inserted gene interfere with the function or activity of another nearby gene? Will it perform as it is supposed to, no matter where it is placed? Is there actually such a thing as an independent gene? Or are genes and other DNA sequences highly interactive and interdependent?  And how can we find out? We do not as yet have the skills to place the gene exactly next to gene A or B or C. All we can do is try to get the gene integrated just somewhere along the chromosomes and hope it will not end up in the middle of another gene or near any regulatory sequences and cause havoc or constant background irritation. The risks involved for the individual are often high and the benefits more a suggestion than a reality.

What is true for gene therapy in humans is equally true for genetic engineering in plants and animals. Experiments have shown that a gene is not an independent entity as was originally thought. For example, a gene for the colour red was the subject of an experiment in Germany in 1990. The colour gene was taken from maize and - together with a gene for antibiotic resistance - was transferred into white petunia flowers. All that was expected was a whole field of 20,000 red flowers; yet not only did the genetically engineered flowers turn red, but tines also had more leaves and shoots, a higher resistance to fungi and lowered fertility, all of which were completely unrelated to the colour gene or the antibiotic resistance gene.

The genetically-modified salmon reared in Scotland is another example. It may be growing fast, but, amongst other side-effects, it is also turning green. Unrelated multiple side-effects of this kind are now termed "pleiotropic effects". They are, by their very nature, completely unpredictable.

In these cases the pleiotropic effects were easy to identify, without molecular analysis. But what happens if the unrelated side-effects are not so obvious - if they only affect protein composition, hormonal expression, nutrient or antl-nutrient concentration, toxins and allergens? Who is going to check all possible side-effects before a plant is released into the environment or placed on our dinner plates? There are no regulations or voluntary practices which check for these kinds of alteration.

Pleiotropic effects like this are being overlooked by using the concept of  “substantial equivalence". Now implemented by the European Union (EU), this concept was advocated by the Organization for Economic Co-operation and Development (OECD) in the early 1990s as the most practical approach to addressing safety questions about foods derived by modern biotechnology.

A crucial 1996 report by the United Nations' Food and Agriculture Organization and World Health Organization stated in its recommendations: ''Substantial equivalence embodies the concept that if a new food or food component is found to be substantially equivalent to an existing food or food component, it can be treated in the same manner with respect to safety.'' The report further states that it there are "defined differences" (e.g. an added gene for herbicide resistance or production of insecticides), the safety assessment should only focus on those defined differerlces. In effect that means, "Don't look for any of the side-effects rnentioned above, just focus on the single trait orJr protein that was altered .  And if this trait or protein was taken from a plant or animal that was part of our food chain, well, then this substance is substantially equivalent and can be passed as safe. "

This approach gives a green light to a flood of engineered food, for which no long-term-risk assessments have been performed, and even short-term risks are swept under a regulatory carpet.
 

IN ANOTHER EXPERIMENT, a red petunia had its red gene multiplied and amplified. Instead of obtaining a deeper red colour, some of the 30,000 flowers were white, some pink, and about half were red. And to confuse the geneticist even more, some of the red flowers reverted to white over time. This was one more experiment which taught us how little we know. It now appears that this so-called "Gene Silencing" occurs when the plant has more than one copy of the same gene, that almost in a form of panic or utter confusion the plant just overrides the controls and puts the genes on ice, not to be used any more.

Besides pleiotropic effects and gene-silencing, there is a third complication -  stability. Experiments with genetically-engineered rice and other plants that had been given an extra gene revealed that over a few generations plants had either more or fewer copies of the gene than the parental generation. Does this mean that plants can perform surgery on themselves and cut the genes out? Or multiply them up and stick them in any odd place? Does that mean that some locations are particularly bad to insert genes into?

There are plenty more examples which show that our understanding of genes and their intricate communication and maintenance system is only just beginning. Yet our ability to chop and splice and multiply strings of DNA, to isolate and sequence thern, has led some scientists and corporations to believe that we are well-equipped with knowledge and expertise. They believe the time is ripe to transform plants and animals into designed and tailor-made commodities.

But who will pay the price? Genes don't just stay put - they might move within the plant;  they will certainly move into other plants by the same means that plants have cross-bred for millennia. For example, rape-seed easily cross-pollinates with wild radish, resulting in healthy and competitive hybrid plants. DNA fragments and even whole genes can be taken up by fungi or bacteria.

There is growing acceptance even amongst proponents of this technology, that gene transfer is inevitable and thus part of the package. Therefore, it is crucial that, if we don't want a particular gene to be passed on to wild or weedy relatives, we should not use it in the first place. This particularly applies to genes for herbicide tolerance and genes that produce insecticides or other chemicals to defend the plant against "attackers" such as bacteria, fungi or viruses.

Plants engineered to tolerate weed-killers will ultimately lead to an ever-increasing use of that weedkiller, either due to the spread of the gene or due to weeds developing their own immunity. For example, annual rye grass (Lolium rigidum) in Australia has developed resistance to Monsanto's weed-killer "Round-Up". For the consumer, herbicide-tolerant plants pose other dangers. Plants frequently sprayed w ith a weed-killer retain the chemical and people will ingest the residues of this chemical as well as its metabolites. Furthermore, plants grown in the presence of weed-killers can suffer from stress and react by over- or under-producing certain proteins or substances. Herbicide-tolerant members of the bean family are known to produce higher levels of plant oestrogens (phyto-oestrogens) when grown in the presence of glyphosate, the active ingredient of Monsanto's Round-Up. Excessive concentrations of these oestrogens present a potentially severe risk to children, as these plant-oestrogens mimic the role of hormones in the body of humans or other mammals eating them. Oestrogens are the female sex hormones—hence plant oestrogens may cause severe dysfunction of the reproductive svstem, especially in boys.
 

PLANTS WITH BUILT-IN insecticide pose further problems. Insects are part of the ecosystem and their numbers are naturally controlled by the abundance or rarity of their food sources and by predators such as birds or specialized insects such as ladybirds. The interaction between plants and insects has been a process of co-evolution rather than of extermination. Over time, plants have developed multiple defences, such as hairiness, thorniness or the production of substances which are toxic to pests. Plants produce an estimated 10,000 different "pesticidal endotoxins" (insecticides) and other nature defence substances. It is important to the plant to get the balance right. Too much defence and there won't be enough energy and substance tc fulfil other vital tasks, such as building seeds or growing strong stems or producing nutrients.

 For some time now it has been standard agricultural practice to produce uniform fields of a single crop in the interests of high yields and efficient planting and harvesting. This has presented a problem to farmers because it sends out a loud and clear "Let's rave . . !" signal to insects that live on that particular crop. They turn up in their thousands for the feast and this is when insects become "pests". Biotechnologists believe they can solve this problem with genes for toxin production. By inserting and permanently switching on these genes, they get plants to produce vast amounts of toxins to fight their own war, so we can forget about spraying them with nasty chemicals.

 Any gene which is permanently switched on and which is outside the plant's own regulatory control can weaken the plant seriously. If a plant can't stop the production of a substance it does not commonly need for survival, it is prone to suffer system breakdown under prolonged stress, such as heat, drought, exposure to herbicides, attacks by pests or heavy rain. If we compare it with the human body, we know that stress and the over-production of adrenalin lead to a weakened immune system due to the underproduction of antibodies.

 Monsanto is facing an increasing number of lawsuits as its geneticallyengineered plants are not behaving as intended or promised. Many of the farmers who grew Monsanto's herbicide-tolerant cotton in 1997 were horrified as the cotton balls fell off their crops, which could be a sign of high stress or gene instability. In 1996, Monsanto’s pest-resistant cotton (NuCOTN) couldn't take the heat-wave of the Southern US and found itself eaten alive by bollworms and their friends. About fifty per cent of the fields needed emergency spraying with insecticides to salvage the crop.
 

GETTING PLANTS TO produce new pesticides causes other problems. Over thirty American groups, including farmers, environmentalists, scientists and consumer groups, are conducting a legal challenge against the Environmental Protection Agency in the US. The challenge is over the licensing of transgenic plants which produce a toxin from the bacteria Bacillus thuringiensis (Bt).

Bt is a naturally-occurring bacterium which can be used as a biological pest-control product. The bacteria produce a chemical which will turn into an active toxin wheneaten by larvae of specific insects. These bacteria have been used for over fifty years by organic farmers when pests threaten to devour their crops. Yet Bt cannot be sprayed on a proactive and regular basis as this will lead to resistance in many insects, rendering the bio-toxin useless to organic farmers. The use of Bt has already led to regional cases of resistance and such developments have been watched closely.

But now the usefulness of Bt is at stake. Modified toxin genes of different strains have been isolated and spliced into corn, potato, cotton, tomato, rape-seed, apple, tobacco, walnut and aubergine plants. As more and more crops are engineered to be pest-resistant, insects feeding on those plants cannot find a refuge. The constant exposure to Bt toxin either kills all the insects off or leads irreversibly to resistance. Both scenarios are highly undesirable. Insects are critical to the entire food chain.  Many animals incuding birds, frogs and hedgehogs live on them.

Many scientists already acknowledge that Bt will become useless within ten years, but biotech companies seem to care little - by then most of the patents on Bt-tedhnology will have expired and they will have lost their lucrative monopoly. They'll simply seek to engineer and monopolize other defence systems.

This kind of behaviour seems to imply that plant life and all other life on our planet is merely there to be experimented with. There seems to be an underlying belief that nature can be controlled. But what if it can't? What if the experiments go wrong? The attempt to create super-races of plants at the cost of biodiversity and locally-adapted crop varieties puts the globe's food supply at severe risk. Genetic engineering is designed for intensive farming, and means big business. At a time when our environment is already suffering extreme stress we should avoid risking the fragile balance or compounding our problems with genetic engineering.

Traditionally, the role of the genetic scientist is analogous to that of the naturalist who studies individual plant and animal species. The science of ecology takes a broader view and studies the relationship between different plants and animals, recognizing the complex inter-relationships that link everything on Earth to everything else. Perhaps now there is a need for a new science - Gene-ecology. Such a science would study the complex relationships between genes in the body as well as their interaction with the inner and outer environment.
 
 

Dr. Ricarda Steinbrecher is a genetic scientist and a member of the British Society for Allergy, Environmental and Nutritional Medicine.

Resurgence No. 188 May/June 1998