Genetic engineering provides hope

In 2023, the EU wants to decide on an amendment to the current genetic engineering law. Approval regulations and labeling requirements must be adapted to the new circumstances because new, precise molecular biological tools are fundamentally expanding the spectrum of plant breeding. The basis for this is the general increase in knowledge in genetics and genome research as well as the methods of targeted gene modifications, which have also made great progress in medicine and microbiology.

Genetic engineering refers to procedures by which the genetic material of organisms is intentionally modified, e.g., through recombination, insertion of additional genes or modification of individual genes, with the intention of making the organisms or their products beneficial to humans. Since adopting a settled lifestyle thousands of years ago, humans have chosen random genetic changes that improved plants in their favor. From a scientific point of view, every breeding – including those using classic methods – is already “genetic engineering” in terms of human benefit.

Applications and products from white (industrial biotechnology), red (medical application) and gray (environmental biotechnology) genetic engineering are widespread and socially accepted. Examples are enzymes, flavorings, vitamins and human insulin. Green genetic engineering with plants has existed in the form of inserted transgenes since the 1980s. The possibility of gene editing with the “gene scissors” CRISPR has existed for around ten years – its discovery was awarded the Nobel Prize in Chemistry in 2020.

Plant Database

With the previously used transgenic technology, additional genes are integrated into the genome. These can come from other organisms. In the newer methods, the “genetic scissors” CRISPR is used as an important new combination tool. A DNA-cutting enzyme, in cooperation with an RNA component, is guided to a specific position in an already existing gene. The accuracy comes from the base pairing of the RNA with the target sequence in the gene. Since the DNA sequence and the properties determined by it are now known for many genes, they can be precisely modified using this principle. The “gene scissors” alter existing genetic material and can be removed after the work is done. From a molecular-biological point of view, the resulting sequence changes cannot be distinguished from mutations achieved in conventional breeding processes.

Green genetic engineering can make agriculture more productive through higher yields and fewer crop losses. In addition, genetically engineered resistance to fungi, bacteria or viruses can reduce the use of pesticides; other improvements such as reduced need for water or fertilizer conserve resources. Potential advantages also result from healthier ingredients (e.g., improved fatty acid composition), better tolerability (e.g., cereals low in gluten or gliadin) and products that can be stored longer (e.g., bananas).

At the end of the 1990s, an international research group developed a special type of rice using genetic engineering: “golden rice”. This variety contains additional genes for the production of provitamin A in the rice grain, which is therefore yellow. In countries where little food other than rice is available, golden rice can counteract malnutrition and prevent children from going blind, for example. Patents and licenses have been granted for cultivation by small scale farmers, and the transgenes can be crossed into locally adapted rice varieties. In 2022, the first major harvest took place in the Philippines.

Another example is a wheat variety in which the asparagine content was reduced by gene editing. When heated, e.g., in toast, this amino acid leads to production of toxic acrylamide. The wheat variety is not yet on the market, but its properties are currently being tested in field trials.

Genetically modified organisms (GMOs) have been cultivated commercially since the mid-1990s. It can be assumed that more than ten percent of global arable land is now cultivated with GMO crops. While only one type of maize is permitted for cultivation in the EU, the global use of green genetic engineering is concentrated in the USA, Brazil, Argentina, Canada, China, Pakistan and Paraguay. Individual African countries are very interested in the potential of the new genetic engineering.

Mutations can always be detected by sequence analysis. However, in the case of small changes that affect one or a few base building blocks, it is not possible to distinguish retrospectively whether they were caused by gene editing or by classic mutation breeding. It is therefore important to test new seeds in a comprehensive certification process for the properties of the plants and their products, their tolerability, ecological behavior and suitability for agriculture, as is the case with new varieties from conventional plant breeding. The ecological risk of an unintentional spread of “newly designed genes” in old crops is extremely low and bears no relation to the ecological risks posed by climate change, wasted resources or the introduction of invasive wild plants.

Genetic diversity is also increased in conventional plant breeding by using high-energy radiation or DNA-damaging chemicals to produce mutations as random variants. Many types of fruit and cereals come from such breeding processes, but European legislation exempts these products from the current Genetic Engineering Act because of their proven harmlessness.

The first transgenic plants contained herbicide resistance genes because of the relatively simple technical feasibility. This increased the resistance of organisms to the weed control agents used, which served the commercial interests of large producers of crop protection chemicals. As a result, increased herbicide use has been attributed to the technology, which was thus linked to health and environmental problems in the public perception. Anti-genetic engineering campaigns have reinforced the bad image and led to restrictive legislation.

Plant breeding should actually be seen as genetic engineering from the start, since plants are modified to suit our needs. This often happens against the “interests” of the plants, such as when mutations prevent the plants from dispersing their mature seeds. This makes a complete mechanical harvest easier, but goes against the natural dispersion of the plant. The methods of genetic engineering are by no means unnatural: the CRISPR principle is used in bacteria to defend against viruses, and the DNA cuts are healed by the plants’ own repair mechanisms. Transgenes are transmitted using a bacterium that has developed the principle of reprogramming plant metabolism in its favor. Gene transfer also occurs in nature: some sweet potatoes contain genes that have been incorporated in this way over the course of evolution.

At the moment yes, but only because large corporations are the only ones who can financially support the long and complex approval procedures in the EU for genetically modified plants. An approval procedure that puts gene-edited plants on an equal footing with those from classic breeding would also open up market opportunities for small or specialized breeding operations.

Conventional agriculture does this by relying on monocultures with just a few species. When used in locally adapted varieties or through turbo-domestication of wild forms, genetic engineering could significantly expand the range of crops and increase biodiversity in the cultivated areas. Green genetic engineering, together with product-based approval regulations, offers many opportunities to make agriculture more sustainable, versatile and resource-efficient.

In principle yes, but the price would be very high: we would be foregoing precise, fast, and inexpensive breeding methods; many breeding goals that cannot be achieved otherwise, especially under the changing conditions in agriculture; and the expansion of the range of interesting crops. Europe would lose out on plant breeding know-how and expose itself to new dependencies in terms of food security.