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Top five myths about genetic modification

GM is not being used to make fishbread Frankenfoods. Dave Lifson/Flickr

The Conversation asked CSIRO scientist, Richard Richards, to look at the top five myths about genetic modification (GM), and correct the public record.

Myth one: GM is just haphazard, imprecise cross-breeding

In genetic engineering, scientists can very precisely select genes and introduce them into their target species. For example, genes that produce insulin for medical use have been introduced into bacteria. Genes from bacteria have been introduced into corn or cotton to dramatically reduce insect damage.

In fact, the most dramatic genetic modifications to our crops occurred naturally thousands of years ago when chance events resulted in hybrids of different species.

Some of these events have resulted in some of our most important crops such as wheat, sugar cane, canola and cotton.

The wheat we consume today, for example, is a natural hybrid of three different wild species. This has resulted in bringing tens of thousands of genes together in several independent events. It is responsible for wheat being such an important crop.

Modern wheat breeders release new varieties after introducing thousands of unknown genes from wild grasses without any regulatory requirements or special testing and with no genetic engineering involved.

This is very haphazard and we do not know what genes are being introduced, apart from the target gene we know is present. The irony is that the precise introduction of a single gene is heavily regulated yet the introduction of thousands of unknown genes from wild grasses into a new wheat variety via traditional breeding methods is regarded as being completely acceptable.

Myth two: GM is a cure-all for more efficient land use and food security

It is important to remember GM technologies are just one of the tools that may be useful. Other important contributions to land use and food security come from traditional breeding, agronomy, land management and sustainability research.

Breeding new varieties of any species requires multiple selection and evaluation methodologies, and there are a lot of conditions at play when developing better wheat.

A new variety has to offer an advantage to the grower, it must have good yields and be adapted to the region where it is grown. It must also have good resistance or tolerance to diseases.

More importantly, it must be beneficial for end users and consumers.

In fact, breeding combines many traits together some of which are simple and some of which are complex. Usually, GM technology contributes only one or two of these traits, although combinations of up to eight genes are now in corn.

Some of these traits may be simply inherited (single gene) - such as plant height or flowering time.

But most are controlled by many genes, including performance in dry environments, grain yield, tolerance to high temperatures, and once the wheat is turned into flour, improved baking quality.

GM technologies are generally only suitable for the single gene traits, not complex multigenic ones. Over time, GM may contribute to factors such as grain yield and drought resistance as we learn more about the basic biology underpinning these traits and identify the key genes to optimise.

Myth three: GM is harmful to the environment

In fact, there have been many environmental benefits from GM.

GM technologies have massively reduced pesticide use in all circumstances where pests have been targeted.

For example, the GM cotton varieties bred by CSIRO that are insect resistant reduce pesticide use by up to 80%.

This reduced use of pesticides has other flow-on effects: less greenhouse gas associated with lower diesel use; less pesticide run-off; less residual pesticides; more biodiversity and improvements in human safety.

Both GM crops and non-GM crops with inbuilt herbicide resistance have also resulted in improved agricultural practices. This has resulted in more efficient water and light use, less soil degradation and improved yields for farmers.

Myth four: GM means creating Frankenfoods

Far from creating radical changes to plants, GM produces defined improvements to existing crop plants that meet a recognised need, such as food quality, increased yield or pest resistance. Strong regulatory systems ensure that GM crops meet stringent standards.

The reality is that scientists experiment with purpose and for beneficial outcomes. There is no use breeding a crop with no market need. Regulatory costs and market demand drive what genes will be introduced into crops.

Almost all introductions will be to improve crop production, quality and health outcomes. Other crops will be modified to change management practices, such as introducing resistance to herbicides.

Often GM technologies don’t involve the introduction of any new genes from another species. Rather they turn the “volume” up or down of a certain gene already present in our crops (rather than introducing foreign genes).

Some of them just silence, or “turn off”, a particular gene. Silencing can be important in modifying grain composition. For example, modifying starches can result in grains that have the potential to reduce the incidence of certain cancers.

Turning up the volume is used to over express some genes, such as those that detoxify excess levels of aluminium in the soil or solubilise nutrients in the soil to improve the nutrition of plants.

Myth five: The GM research agenda is run by big multinationals

GM research has contributed greatly to our understanding of how plants function and this has delivered tremendous benefits to both traditional breeding and to opportunities for GM crops.

However, commercial introductions are extremely costly due to the extensive regulatory processes required by different territories before GM crops can either be grown or utilised for feed and food purposes.

The public sector, through institutions such as CSIRO, also expends considerable research dollars on GM research.

Regardless of this, GM products will not be adopted by growers if they negatively impact their farming operations or they do not capture value in their farm products.

It is largely up to farmers which GM varieties they grow and market. More importantly, if consumers do not accept them, then they will not be grown.

By way of example, the adoption of insect resistant varieties and herbicide resistant varieties by farmers has been spectacularly successful.

It must represent some of the fastest technology adoption ever by farmers.

This has occurred because these varieties offer genuine benefits in terms of the cost, timeliness and sustainability of their overall farming operations.

Despite this, traditional varieties remain available and can be maintained if farmers wish to continue growing them for a particular performance or market demand.

The vast majority of funding for CSIRO’s research relating to gene technology comes from government funding, non-profit organisations and research centres.

There is investment from private companies but investment from all these sources makes up less than 0.2% of CSIRO’s total budget of $1 billion.

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