GENE TECHNOLOGY - AN OVERVIEW

Graeme King, Senior Scientist,

Ministry of Agriculture and Forestry

July 1998

Introduction

Over the past 25 years, gene technology has been changing the way humans understand and use biology. What is gene technology? How is it being used in agriculture? What's coming up in the future? It is not my intention today to advocate for or against the use of gene technology, but rather to address these questions from an information perspective. The decisions or how gene technology is appropriately used are ultimately for society to decide.

What is gene technology?

Many people are now familiar with the initials DNA - the abbreviation of the chemical substance that carries genetic information. Gene technology is the term used for a series of techniques that can be used to alter the basic genetic makeup of living things by inserting small sections of DNA. This is done by identifying the DNA carrying the information for a particular trait (called a gene), cutting it out from all the other genes (there can be tens of thousands of genes in living things), copying it many times, and then inserting it into the genetic material of the same or another species of organism. The information in a gene guides the production of a protein (usually an enzyme) which, in turn, controls a chemical reaction in the organism.

While the outcome of many of these modifications could be achieved by traditional breeding, gene technology provides a more direct method of achieving a specific change. In contrast to traditional breeding, gene technology allows researchers to introduce genes originally derived from any source (e.g. a microbe, plant, animal, or even a completely synthetic gene) and not just closely related organisms. This is possible because DNA from different sources has the same chemical structure and follows the same rules in performing its functions. This feature gives breeders a much wider choice in their search for desired genetic material. It is also the reason that some people have concerns about the safety and ethical implications of gene technology.

How has gene technology been used?

a) Research and development

Since the first demonstration of these techniques in the early 1970s, gene technology has proved to be a powerful research tool. It is now a key component of many biological research programmes because it allows researchers to determine how individual genes are controlled and to ascertain the function of specific proteins. An example may be helpful. Since the early 1960s, it was known that tomatoes produced a huge amount of one particular enzyme during ripening. This led to the belief that the enzyme controlled softening. Gene technology was used to turn off the enzyme concerned but the fruit still softened at much the same rate as the unmodified tomatoes, although they didn't over ripen and fall apart completely. The enzyme is no longer considered the major controller of softening, and so research on the control of fruit softening can be directed elsewhere.

Following the introduction of gene technology, its potential to introduce novel characteristics into microbes, plants and animals has been rapidly explored. The first efforts focused on microbes because of their relatively simple structure. A number of commercial processes now use microbes which have been genetically modified to produce materials which they would not produce naturally (e.g. drugs such as human insulin, growth hormone, animal vaccines and a range of industrial enzymes).

The genetic modification or farm animals and fish is still largely at the experimental stage. The aims of the research include enhancing resistance to infection, and. increasing growth rate. A method for producing human health products from the milk of farm animals is at an advanced stage of development. For example, New Zealand recently approved an experimental trial whereby ewes were inseminated with the semen of genetically modified rams developed in Scotland. The milk of the offspring will contain a human protein that will be isolated and used to treat cystic fibrosis and emphysema. New Zealand was chosen for this trial because the manufacturing company wanted the marketed form of the protein to come from sheep with no history of scrapie. A manufacturing flock for commercial production is expected by 2001.

Field trials of genetically modified plants began in 1986 with the growing of tobacco modified for herbicide tolerance in USA and France. Trials continued at relatively low levels until 1992, and subsequently have increased markedly each year. By the end of 1997, there had been over 25,000 field trials on more than 60 crops with 10 traits in 45 countries. More than 70% of the trials were in USA/Canada, but most major landmasses have now had at least some trials of genetically modified plants. For comparison, New Zealand has approved about 50 field trials over the same period.

The major crops that have been genetically modified are maize, tomato, potato, soybean, squash/melon, cotton, tobacco, canola and sugar beet. The majority of traits modified to date are tolerance to specific herbicides (e.g. Roundup), and resistance to pests and diseases. There has currently been much less emphasis on quality traits such as improved processing.

b) Commercialisation of genetically modified crops

The first commercial release of a genetically modified plant (tobacco with virus resistance) occurred in China in the early 1990s. In l994, the USA released onto its domestic market the FLAVRSAVR tomato - a tomato that could be held longer on the vine before picking and was less prone to over- ripening. The latest data of USA commercial plantings is revealing. From small beginnings in 1994, currently between 25 - 40% of all USA plantings of corn, soybeans and cotton are genetically modified. These crops and their products are now being moved onto world markets.

Other countries growing commercial crops of genetically modified plants include China, Canada, Argentina, Australia and Mexico.

Gene technology in New Zealand agriculture

Since the mid 1980s, New Zealand has invested heavily in gene technology, primarily for research and development purposes. The bulk of funding for this research has come from government, initially through MAF and DSIR, but subsequently from the Public Good Science Fund following the restructuring of science in 1992. Much of this investment underpins industry research strategies aimed at maximising economic returns to New Zealand from international trade.

The research effort in animals has focused on identifying genes controlling growth and reproduction, especially the control of milk production in dairy cows. Research in plants is more commercially advanced with a range of crops now at the field trial stage. Just some of the crops being worked on include pasture grasses (virus and pest resistance), fruit and vegetable crops (herbicide tolerance, pest and disease resistance, improved quality traits) and ornamentals (novel flower colours).

None of this research has yet been commercialised. The first genetically modified crops developed in New Zealand are likely to be considered for release early next century. However, it is possible that some growers may wish to import and grow seeds that have been genetically modified overseas before that time.

What's in the research pipeline overseas?

The emphasis to date has been mainly on traits which are designed to reduce farming inputs (e.g. herbicide tolerance. resistance to pests and diseases). However, the trend in research and development is now more strongly towards altering quality or "output" traits which have direct consumer benefits (e.g. improved flavour, texture, nutrition, processing, or health benefits) This year in the USA, insect resistance and herbicide tolerance will be stacked together in some varieties. Within the next few years, there are likely to be multiple stacked traits e.g. crops that are herbicide tolerant, insect resistant and have improved nutritional quality.

Further out, but already under research and development, are crops which produce entirely new products not normally associated with agriculture. These include oral vaccines (e.g. potatoes that contain a protein to immunise people against hepatitis B), and the production of chemical reagents (e.g. avidin protein) and plastics in plants to replace less sustainable production systems. A key question that remains is how will gene technology be integrated into agricultural systems?

How will gene technology be integrated into agricultural systems?

Gene technology will not replace conventional breeding - it provides another option for introducing genetic variation at the beginning of a breeding programme. Gene technology may not be economically viable or appropriate in many instances (e.g. where sufficient genetic variation already exists within a particular species). Further, in the foreseeable future there will always be a market for non-genetically modified foods in organic farming systems.

Gene technology may change farming and distribution systems. In both the USA and Australia, manufacturers require farmers to implement specific management procedures (e.g. the planting of a specified percentage of non-modified crop) to slow the development of resistance to the toxins inserted into insect-resistant crops. High value crops will need to kept segregated from conventional crops right through the production chain to capture the value added. Each of these issues will need to be considered on a case-by-case basis as the technology becomes available here in New Zealand.

Gene technology is very expensive. To be commercially successful, gene technology must add value over and above any systems it is designed to replace - there must be incentives for technology and seed production companies, farmers, distributors/processors, and consumers. Right now judging from the expansion in US plantings over the past four years, technology companies and growers are finding value in genetically modified crops. However, the benefits to consumers are not clear in many instances (e.g. there is no direct benefit to consumers from a herbicide tolerant soybean) As key end users of gene technology in the food and fibre industries, consumer concerns must be carefully considered.

What are the consumer concerns?

Two key issues dominate the use of gene technology internationally, particularly its use in food - safety and choice.

a) Safety

To be acceptable to New Zealand society, new technology must be safe to both people and the environment. Based on the experimental information and commercial experience to date, there are no unique risks just because a crop has been genetically modified - the risks come from the characteristics of the modified crop as they do for crops bred by other breeding processes. However, the long term effects of using gene technology in food crops cannot be completely predicted, and no food can ever he proven safe for all people in all circumstances. This worries some people who believe that genetically modified foods should not be commercialised at this stage because too little is known about the scale-up effects on the environment in moving from small-scale field trials to full commercial production, or the long term effects of inserted genes on the behaviour of whole organisms.

In New Zealand, the safety of genetically modified food crops will be assessed by two statutory bodies. The Environmental Risk Management Authority (ERMA) will assess the safety to people and the environment of all genetically modified organisms for use in research or for release into the environment. The Australia New Zealand Food Authority (ANZFA) is responsible for assessing the safety of all foods derived from gene technology before they are marketed. Both ERMA and ANZFA will use a. case-by-case, risk-based assessment of safety, and both allow for public input into their decision-making processes.

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b) Choice

Many people all over the world, but especially in Europe, also have concerns about ethical and social issues surrounding the use of genetically modified foods. These include the ethics of moving genes between species, impacts on third world economies that depend on particular products that could be substituted by genetically modified organisms (e.g. vanilla), and the consumers right to know about which foods have been genetically modified so that people can have an informed choice about purchasing based on their specific concerns. Meeting these concerns presents- an immense challenge to the commercial use of agricultural gene technology.

An example of what this can mean in practice is the experience of Sainsbury/Safeway in the UK. In 996. Sainsbury and Safeway (two retail foods chains) successfully marketed Britain's first genetically modified food - a puree produced from tomatoes that has been genetically modified to reduce wastage. The research leading to the final product was described in magazines from 1993. There was a defined consumer benefit - the product was slightly cheaper than the regular puree. Consumers were informed by placing labels on the can declaring that the product was genetically modified and outlining why the genetic modification was made. In store, leaflets were available explaining the process and the product was sold alongside the regular product, enabling the consumers to make a truly informed choice. Sainsbury now report that their modified paste outsells their unmodified paste by more than 2: 1. The ethical and intelligent marketing of genetically modified foods producing positive benefits will be essential if consumers are to accept genetically modified foods.

Conclusion

Gene technology is a global technology. It has now been widely used for 25 years in research and industrial applications. It has only relatively recently been commercialised in food crops, and is unfamiliar to many consumers. While seemingly well accepted in the food chain in North America, the acceptability of genetically modified foods elsewhere will likely depend on the benefits they deliver and how they arc marketed to consumers.

TOC

Contact for Enquiries

Dr Sharon Adamson
Manager, Innovation Policy
Ministry of Agriculture and Forestry
PO Box 2526
Wellington
NEW ZEALAND

Phone: +64 4 894 0618
Fax: +64 4 4 894 0741
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