Tea are new biotechnologies developed to make cultivated plants more resistant to pests and drought. A solution that, however, raises concerns in light of certain scientific studies. Tea are new biotechnologies developed to make cultivated plants more resistant to pests and drought. A solution that, however, raises concerns in light of certain scientific studies.
In common parlance they are called "new GMOs"; the scientific term that identifies them, however, is Tea, an acronym for Tecniche di evoluzione assistita (assisted evolution techniques), or in English Nbt (New breeding techniques) or Ngt (New genomic techniques).
These are new biotechnologies that have developed since the 2000s: the main techniques are cisgenesis and genome editing; the latter includes the Crispr/Cas9 system, developed by scientists Emmanuelle Charpentier and Jennifer Doudna, who in 2020 received the Nobel Prize in Chemistry for their discovery.
The difference between these new techniques and GMOs developed from the 1970s onwards is that, whereas GMOs involve inserting sequences of genes from other species into an organism's genome — i.e. foreign DNA — Tea intervene in an organism's genome using genes from organisms of the same species: the result is therefore not a transgenesis, as in the case of GMOs, but a mutagenesis, a mutation.
One of the central issues surrounding Tea concerns precisely whether or not these new techniques should be equated with GMOs, and consequently how they should be regulated on the market: should they be subject to the same rules as GMOs, or is a new regulatory framework needed? At present, a ruling by the European Court of Justice applies, which established that Tea are governed by the same European Union legislation as GMOs, following the precautionary principle: before any genetically modified product or organism may be placed on the EU market, it undergoes an authorisation procedure during which its safety for humans, animals and the environment is carefully assessed. In 2021, however, the European Commission launched a consultation process with a view to establishing a new regulatory framework for Tea, and the legislative proposal was expected on 5 July.
In Italy, growing GMOs for commercial purposes is prohibited, but marketing their products is permitted, subject to labelling rules. Last May, an amendment was approved as part of the drought decree giving the green light to Tea trials not only in the laboratory but also in the field, as is already the case in the United States, Canada, South America, Japan, the United Kingdom, Belgium, Sweden and Spain.
Like transgenesis techniques, mutagenesis techniques are also championed with the aim of making plants more resistant to disease and pests, and increasingly to climate change, which makes extreme events such as drought or, conversely, flooding unpredictable. Plants obtained through mutagenesis would therefore require less use of fertilisers and pesticides, in line with the objectives of the European Green Deal. Not everyone, however, agrees with this view. At European and Italian level, green parties, environmental organisations and organic farming associations oppose the deregulation of these techniques relative to GMOs, on the grounds that they would entail the same risks and the same problems as transgenic organisms, and instead propose other solutions to address the contemporary challenges of agriculture and food security.
Below we set out the different views through the contributions of some experts in the field.
Luigi Cattivelli is a plant genetics specialist, director of Crea Genomics and Bioinformatics, and coordinator of Biotech, the first major Italian project dedicated to plant genetic improvement, funded in 2018 with 6 million euros by the Ministry of Agriculture and concluded in 2021. The project involved crops of importance to Italian agri-food, including grapevine, olive, apricot, peach, cherry, apple, pear, tomato, aubergine, basil, artichoke, wheat, rice and poplar. The research yielded several results, among them tomatoes resistant to the germination of parasitic plants, durum wheat immune to fungal diseases, seedless grapes and aubergines, and oranges enriched with antioxidant compounds.
"It is not correct to equate Tea with GMOs," explains Cattivelli. "In the case of transgenic soya or maize, for example, the gene inserted into the plant species comes from a bacterium. The new genomic techniques intervene in the organism only with genes from organisms of the same species, producing a mutation. Mutation in nature is the basis of evolution — or, to put it another way, evolution is the result of mutation."
Tea would therefore contribute to significantly shortening selection timescales, making it possible in just a few years to achieve what previously, in tree crops, required several decades. "In nature, plants do not evolve to be eaten by humans; it is humans who have been domesticating them for millennia to produce food, so much so that we can say there are no plants in commerce with a genetics older than 40 years."
The Biotech project has also yielded results with the vine: "The Glera grape variety used to make prosecco is susceptible to many diseases. Inserting a gene from a disease-resistant vine variety makes it possible to obtain a plant that does not fall ill, yet retains all the characteristics of the Glera variety." And all of this can be done, according to Cattivelli, without risks — or at least with the same risks as other crops — and in a more predictable way than what occurs in nature. Moreover, according to Cattivelli, the result is the same: when faced with a mutation, it is impossible to trace back how it occurred, whether naturally or in a laboratory.
What becomes of biodiversity and traditional farming practices in all of this? "Biodiversity is a concept that has a past and a future, because we create and select biodiversity every day. It is right to preserve traditional agricultural techniques, but this will not be the future — or, at any rate, it will not be the only future. With global warming it makes little sense, for example, to grow an ancient grain that developed in a climate certainly colder than today's; but I can take a characteristic of an ancient grain that I consider functional and insert the gene responsible for it into the wheat variety I want to make resistant."
Salvatore Ceccarelli was Associate Professor of Genetic Resources and subsequently of Plant Breeding at the Faculty of Agriculture of the University of Perugia until 1987; for thirty years he conducted research at the International Centre for Agricultural Research in the Dry Areas in Aleppo. The author of numerous scientific papers, he has carried out research around the world on the adaptation of crops to climate change, starting from genetics.
Regarding assisted evolution techniques, he shared with us several concerns that, in his view, suggest refraining from permitting the use of these techniques in agriculture and from deregulating their experimental use: "The first is linked to around twenty publications in the most important scientific journals demonstrating that the Crispr/Cas9 technique produces mutations at points in the genome other than those of the gene on which the intervention was made, with consequent unwanted side effects; in 2021, a paper was published showing that Crispr-Cas9 also causes chromosomal damage similar to that which arises at the onset of the processes leading to the development of tumours in humans."
"The second concern," Ceccarelli continues, "relates to the fact that the agronomically relevant traits of an organism are controlled, in many cases, not by a single gene but by many genes that may also belong to different chromosomes; furthermore, these traits are not purely genetic matters, but are also heavily influenced by the surrounding environment."
The professor continues: "The third concern addresses the evolutionary dimension. The central question is not whether Tea are or are not GMOs: the point is that both technologies suffer from the same weaknesses. The majority of GMOs, such as soya and maize, are developed with herbicide resistance, but several studies have shown that, over time, weeds also evolve to develop this resistance, thereby requiring ever greater use of herbicide. The result, therefore, is exactly the opposite of the objective that was set when creating the genetically modified organism." On the basis of evolutionary theory, according to the researcher, Tea cannot represent a lasting solution to plant susceptibility.
"The final concern relates to the fact that, in order to move from one organism to another, genes need a vector: these are small pieces of RNA or DNA that have nothing to do with the organism in question, and which in turn integrate into the host's genome alongside the resistance genes — which means that Tea are, to all intents and purposes, GMOs." According to Ceccarelli, Tea would not address the unpredictability of climate change, which influences the spread, growth and survival of the diseases, insects and weeds that attack plants.
The solution, to which the scientist dedicates his research in close collaboration with farmers, is instead that of diversity between crops and within crops, which reaches its fullest expression in "evolutionary populations", and which Ceccarelli explains as follows: "This practice consists of sowing different plants of the same species in the same field. In this way, a fungus or an insect that arrives in that field can attack a susceptible plant, but it takes longer to 'find' it and therefore to spread. By doing so, I minimise damage to the crop because in the meantime the plant will grow and the farmer's harvest will be guaranteed without chemical intervention; I also prevent the parasite from evolving, because it has had the opportunity to reproduce. At the same time, this practice also allows the plants to cross with one another to create new genotypes and become more resilient. The mixing of seeds is not static but dynamic: at the end of the harvest, the seed — which will no longer be the same as the starting one — is sown again, and over time the plants will become a population with greater evolutionary potential."
Evolutionary plant breeding aims to return control of seeds to the hands of farmers, with an economic advantage but also a biological one, "because there is no better seed than one that adapts year after year." "This is not a romantic argument — behind this practice lie 100 years of scientific study: by mixing seeds, one applies to agriculture and to plants the same strategy applied to financial investments." A solution that, as the professor finally notes, the European Commission envisages for organic farming with the recognition of the value of "heterogeneous biological material," and which has already been successfully implemented by many farmers who are part of small local supply chains.