Genetic engineering in plants: what exactly is it?

A short introduction to biology, biotechnology and genetic engineering with information on green genetic engineering and the principle of coexistence.

Basics of biology

Almost all living things on earth are made up of a multitude of cells. We can easily understand this in the human body: Every hair grows from a hair root cell and when sunburns, dead cells of the top layer of skin are detached. An adult human is made up of 100 trillion cells! Since we are constantly “losing” cells – just think of the hair in a brush or the sun-burned skin on the shoulder – around 50 million new cells are formed every second.

The complete genetic material, half of which we received from father and mother, is stored in every human cell. This blueprint of our body is therefore identical in all 100 trillion cells. How can it be that the cells look so different and have different functions?

The secret lies in the genome, the blueprint itself. The blueprint is structured like a lexicon that includes several volumes. Humans have 46 “volumes”, they are called chromosomes. Of the 46 chromosomes, 23 each come from the mother and the father. Each chromosome can be thought of as a coiled long chain, because it consists of a long thread that is strongly twisted and folded. That thread is DNA. If you unfold or untwist it, you can see the links of the chain. Nature only knows four “links in the chain”, the so-called nucleotides. They are called adenine, guanine, cytosine and thymine. The four nucleotides are so small that each consists of only about 36 atoms! When the nucleotides follow one another in such a way that they make sense to the body, like letters a word and words a sentence, this section of a chromosome is called a gene. Chromosome 7, for example, is made up of around 158 million nucleotides and is estimated to contain between 1,000 and 1,500 genes.

Today it is assumed that humans have a total of around 30,000 genes. Of these 30,000, only those that are needed are read in each cell. In this way, the hair root cell can read the genes that make a hair grow. And a cell in the pancreas reads the genes that make stomach acid produce.

Every living being has its own genes and a number of chromosomes typical for its species. The smallest units of the genome, the nucleotides adenine, cytosine, guanine and thymine, are identical in almost all living things. Regardless of whether it is human, animal or plant. This is why one speaks of the fact that the genetic code is “universally valid”.

Basics of biotechnology

Biotechnology stands as a collective term for an almost unmanageable variety of processes, products and methods. Some biotechnological processes have been used for centuries, for example in the production of alcoholic beverages using yeast or cheese using lactic acid bacteria. This part of biotechnology uses living organisms and their metabolic products, for example for the production of food and drugs.

Diagnostic methods for decoding, marking and isolating parts of the genetic material are also counted among the “biotechnological methods”. This includes, among other things, the “genetic fingerprint”, which has gained great importance in forensic medicine and classic plant and animal breeding. Diagnostic biotechnology does not create a direct recombination, nor are genetically modified (GM) organisms created.

Basics of genetic engineering

The term “genetic engineering” describes processes with which the genetic material of organisms can be artificially changed. For example, the genome of the organism can be recombined or parts of the genome of another organism can be transferred. The genetic transfer of genetic information takes place either directly (for example by microinjection, microprojectile bombardment) or via so-called vectors, such as viruses and bacteria. With the discovery that the genetic code applies universally to (almost) all living things, it became possible to transfer DNA across biological species boundaries. One then speaks of the transfer of foreign genes, which creates a transgenic organism.

The aims of genetic engineering applications are, for example, the improvement of seeds, the use of genetically modified microorganisms in food production and the production of medicines for humans and animals. For example, the gene for human insulin could be introduced into bacteria and thus insulin could be produced on an industrial scale. For example, vitamins, vaccines (hepatitis) and hematopoietic factors are now produced using genetic engineering methods as standard. Medical diagnostics is now also hardly imaginable without genetic engineering.

Genetic engineering can be divided into the following three major areas of application:

  • Green genetic engineering: genetic engineering processes in agriculture that are used for plant breeding and animal breeding.
  • Red genetic engineering: genetic engineering methods in medicine for the development of diagnostic and therapeutic processes as well as for the production of drugs for humans and animals.
  • Gray or white genetic engineering: The use of genetically modified microorganisms to produce enzymes or chemicals for industrial purposes, the food and feed chain, in microbiology and environmental protection technology.

Importance of green genetic engineering

In 1995, genetically modified oilseed rape was planted commercially for the first time in Canada. In the following year, the commercial use of transgenic soy followed in the USA. In the meantime, transgenic crops are grown worldwide on around 189.8 million hectares (source: ISAAA Briefs No. 53-2017, June 2018) of agricultural land. This corresponds to around 13 percent of the world’s arable land (source: FAOSTAT, July 2019): Transgenic soy, maize, cotton and rapeseed varieties that are cultivated on (more than 10 million hectares each) are of the greatest importance. Genetically modified varieties of alfalfa, sugar beet, papaya, pumpkin, potatoes, aubergines and apples are of minor importance. The main growing areas are the USA, Brazil, Argentina, Canada, India and Paraguay. In total, genetically modified plants were grown in 24 countries in 2017, including two EU member states. In addition, z. For example, genetically modified poplars are also grown in China.

Currently only one genetically modified plant is approved for cultivation in the EU. It is maize of the MON810 variety, which contains a gene from the soil bacterium Bacillus thuringiensis (Bt). It can therefore produce an insecticidal substance, the Bt protein. Bt maize is thus able to kill the European corn borer pest before it is damaged. In addition to the approval under genetic engineering law, the genetically modified plants for commercial cultivation, like all new varieties, also require variety approval under the Seed Traffic Act.

In 2017, Bt maize MON810 was grown in two member states of the EU. In Spain, the transgenic maize was harvested on an area of ​​124,227 ha and in Portugal on 7,308 ha.
In Germany, until 2011, small areas were grown with transgenic maize MON810 and the genetically modified potato of the Amflora variety, which is no longer permitted in the EU. There has been no commercial cultivation of genetically modified plants in Germany since 2011.

What is meant by environmental risks?

Protecting the environment from the possible negative effects of GMOs is a key political objective of the European Union and other countries. In the case of product development from or with genetically modified organisms, genetic engineering law is based on the concept that provides for a step-by-step procedure from the laboratory and greenhouse via limited releases to placing on the market. In this way, possible risks should be identified at an early stage of development.

Social protests are particularly loud in connection with the cultivation or the experimental release of genetically modified plants. It is often feared that these could multiply once they are (to a limited extent) released into the environment. Environmental risks could then lie in the fact that the genetically modified plants disrupt the prevailing equilibrium in a certain ecosystem, for example if the properties introduced in the laboratory should be transferred to other species.

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