A technological timeline
Crop plants are improved by generating genetic variation that leads to beneficial traits. Plant breeders traditionally achieved this by crossing different varieties of the same plant species. These approaches alter many genes; the result is that traditionally-bred plants contain both advantageous and deleterious traits. Removing disadvantageous traits before the crop can be commercialized is a costly, time-consuming process.
In the 1980s, transgenic genetic modification technologies were developed. These rely on pieces of DNA from one species being integrated into the genome of a crop. Such genetically modified (GM) plants are highly regulated internationally. In South Africa the legislation governing these plants came into force in 1999. The use of GM technology in South Africa – and other countries – has been highly successful.
For example, it has led to South Africa doubling maize productivity, making it a net exporter of this commodity. This contributes to food security and also generates foreign income, which reduces the country’s trade deficit.
But the regulations governing GM plants are onerous: only large agricultural biotechnology companies have the resources to commercialise them. This is done to the eliminate risk that GM plants containing new DNA are harmful for health or to the environment.
Because of this, all GM plants licensed for commercial use in South Africa come from a small number of international companies. Not a single locally developed product has been commercialised during the past three decades, despite South Africa being an early adopter of the technology. This hampers the development of novel crops and the improvement of traditional crops, especially for emerging and subsistence farmers in sub-Saharan Africa.
That’s why newer tools like genome editing are so exciting. They can be used to introduce genetic variation for crop improvement in a fraction of the time it would take using conventional methods. Some forms of genome editing are transgenic in nature, while others aren’t because they don’t involve the insertion of foreign DNA into a plant.
This approach mimics the effect of traditional plant breeding, but in a highly targeted manner so that only advantageous traits are introduced. For example, genome editing is being used to produce peanuts, soybean and wheat that do not produce allergens.
It’s working well. Despite the technology only being available for a decade, some crops produced using genome editing are already on the market in some countries, including soybean and tomatoes which are healthier for human consumption.
A proposed regulatory approach
Regulatory authorities around the world have taken either a process- or a product-based approach to regulating GM crop safety. A process-based approach examines how the crop was produced; a product-based approach examines the risks and benefits of the GM crop on a case-by-case basis.
We believe that a product-based approach makes most sense. This is because a process-based approach could lead to the strange situation where two identical plants are governed by very different regulations, just because they were produced by different methods. The added regulatory burden imposed by this approach will also hamper innovation in developing new crops.
Our approach would mean that any plant with extra DNA inserted into the genome would be governed as a GM plant. Plants with no extra DNA added and that are indistinguishable from conventionally bred organisms should be regulated like a conventionally produced crop.
This is the most rational way to regulate these different types of organisms, as it adheres to the principles of science-based risk analysis and good governance.
Science-based risk analysis should return to the heart of regulation: concrete risk thresholds should define regulatory triggers.
ssociate professor at Stellenbosch University, Dave Berger is a professor in molecular plant pathology at the University of Pretoria and enior researcher for the Council for Scientific and Industrial Research.
This article was originally published on The Conversation.
Image: Genetically modified, virus-resistant papaya. Photo: Alliance for Science