2023-06-06 07:09:00
8 min.
The decline of the Mesopotamian civilization, 4,000 years ago, coincided with a long drought of centuries. Agriculture died and, without food, the people migrated to more fertile soils. The reasons for that climate change They are different from those of today, driven by human action, but the consequences could be similar. They already are in some parts of the planetand science takes note:
“You have to improve the plants so that they are more resistant to droughtto the temperatures and pests that appear because the thermal cycles have changed,” says Cristina Nieto, a researcher at the Plant Genetic Resources Center of the National Institute for Agricultural and Food Research and Technology (INIA-CSIC).
Teams like his are already working so that the cultivation of wheat or tomatoes in Spain is possible even in years when there is little rain and the dammed water is not enough for all irrigation. Efforts range from “breakthrough” innovations, such as the gene editing of seedsto more conventional measures, such as the selection of suitable varieties. For all this it is necessary to broaden the knowledge about the basic functioning of the plants. The race against climate change has already begun.
Tomatoes that can withstand up to 18 days of extreme drought
One of the advances has been developed in CSIC laboratories between Madrid and Valencia. “We have spectacular results, resistance to 18 days of extreme drought“, reports Armando Albert, a researcher at the Rocasolano Institute of Physical Chemistry (IQFR), who leads the project together with Pedro Luis Rodríguez, from the Institute of Plant Molecular and Cellular Biology of the Polytechnic University of Valencia.
The method they have patented consists of a drug which, when sprayed on a tomato plant, for example, influences the transpiration of the plant, which is produced through small pores called “stomata”. That way, they breathe, but the other way around: they capture CO₂ and expel oxygen. “For every molecule of CO₂ that enters the plant, about 100 molecules of water escape into the environment,” Albert explains to RTVE.es.
The research to try to avoid this loss led them to abscisic acid, which is the hormone that is naturally responsible for opening the stomata, but also for the roots to grow to look for more water, among other mechanisms to avoid dehydration of the plant. . That knowledge has led them to create a “molecule that performs the same functions as abscisic acidusing the techniques that are used to make an antibiotic today”, in short, to invent a “drought drug”.
Albert and Rodríguez’s team has been able to advance much faster than in the complicated trials in humans and, thus, they have already verified that by applying the molecule to a tomato plant, a wheat plant or any other, they better withstand drought because they close the stoma without compromising the essential processes of the plant.
But, how to apply the ‘medicine’ only to the crops that interest us, without closing the stomata of the rest of the plants and altering biodiversity? Genetic editing was added to the chemical solution. “We have designed a protein that recognizes our molecules in a specific way and not abscisic acid, so that only the plants that carry our receptor, our modified protein, are activated”, continues the IQFR researcher, who adds that, thanks to the transgene, the desired effect is achieved “with a very small amount” of the drug.
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From the controversial transgenic to genetic editing with CRISPR: “They have nothing to do with it”
This project, however, can now find an obstacle in the restrictive regulations of the European Union on transgenics and gene editing. More and more scientists and other voices in favor of these tools among member countries —including the Minister of Agriculture, Fisheries and Food, Luis Planas— are calling for an open hand, given the improvement in techniques in recent years and, especially, in the face of problems such as drought.
In fact, varieties such as the maíz Drought Gardwhose crops have a superior yield in dry conditions, while Argentina has begun to sow the transgenic soybean Hb4, which contains a sunflower gene and whose development was financed by the government, as listed by the professor at the Polytechnic University of Valencia and disseminator, José Miguel Mulet, in Objective Planet of the Channel 24 Hours. The EU would not allow the production of these products, although it would import them:
“That means that during these last 20 years we have been importing soybeans and corn resistant to herbicides, which could not be planted here. As it stands, soon we are going to buy drought-resistant wheat and soybeans that our farmers will not be able to plant, unless we change the law”he commented.
The biotechnologist highlighted the difference between the already known transgenics and the new, safer CRISPR gene editing techniques. “A transgenic does a ‘copy and paste’ of a piece of DNA from one organism to another and what CRISPR does is correct the organism’s own DNA. Let’s say you make a surgical change, such as removing a letter or two letters from the DNA or put one or two letters of DNA, but foreign DNA is not involved,” explained Mulet, who has worked in the laboratory with these techniques to improve the resistance to drought in plants.
For this reason, in Japan, where important controls were imposed on transgenics, they have been lifted for the new techniques, considering that “in terms of safety” they are very similar to traditional production methods. The Japanese are already consuming genome-edited tomatoes, while “Europe temporarily considers that CRISPR is the same as a transgenic. And from a scientific point of view, it is an absolute aberration. These are techniques that have nothing to do with it,” he explained. .
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Old seeds to get new seeds
Other routes will seem less ‘futuristic’, but they can be just as sophisticated and very effective in the face of increasingly frequent and extreme droughts due to climate change. “Gene editing techniques, which are the revolution, must be combined with natural variability,” claims Cristina Nieto to talk to us about the “agrodiversity” and the potential that Spain may have to lead this field.
Nieto works at the Center for Phytogenetic Resources, a kind of “seed bank” where the varieties of cereals and legumes that were cultivated in Spain more than 50 years ago are stored and classified. “The green revolution improved the varieties to make them much more productive, but in the end they were reduced to fewer varieties,” he says. They are now “less genetically diverse.”
Thus, by searching and studying the archives, they try to find seeds that were better adapted to local conditions, where the arid climate is not a novelty either: “We can have a wheat that has adapted to growing in Seville and another wheat in Zaragoza. So, with that genetic diversity, what we are going to do is look for the characteristics that interest us.”
They also work in coordination with other countries of the European Union to standardize the information: “They try to make it interchangeable between the banks so that, if there is a wheat in Poland with a characteristic that interests us, we can identify it and work with it,” he points out. the researcher, who recalls that knowing in depth the molecular biology of each plant may be the key to improving the efficiency of crops. She also does not rule out that in the future crops more typical of hot African countries, such as sorghum or millet, will become popular.
“There will be no magic bullet”
Applied science to adapt plants to drought is now a reality, as is climate change. If we ask about the future, experts remain hopeful that a fate like Mesopotamia will be avoided in the medium term.
“There will be no magic bullet, There is no single solution. In other words, transgenic seeds or CRISPR will help. But the improvements in irrigation as well”, insisted Mulet, emphasizing the advances that have already been made: “I come from a family of orange growers and before it was irrigated by flooding the field.”
For his part, Armando Albert, from IQFR-CSIC, hopes to achieve future advances, both from genetic modification and molecular biology, which can offer cheaper and more scalable solutions for agriculture and, by extension, for food. “Unless we start eating insects or planting on the moon, we will necessarily have to optimize the use of water, and biotechnological applications achieve spectacular results”ditch.
Nieto celebrates that a social and political conscience has finally awakened in this regard: “No change is going to be immediate and reality has caught up with us.”
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