Using CRISPR genetic editing tools, researchers got wheat plants to produce larger quantities of one of their own natural compounds. The discovery can represent a savings of up to 10% in the use of fertilizers.
A team of scientists has developed wheat plants capable of stimulating the production of their own fertilizer, paving the way for a less polluting agriculture For air and water at the global level and with lower costs for farmers.
Technology, developed by a team led by Eduardo Blumwaldresearcher at the University of California, was presented in a published in the magazine Plant Biotechnology Journal.
Using CRISPR genetic editing tools, the researchers got the wheat plants to produce larger quantities of one of the their own natural compounds.
When excessive to the ground, the compound stimulates certain bacteria to turn the nitrogen present into the air into a assimilable form by plants. This process is called nitrogen fixation.
In developing countries, this discovery may represent a important contribution to food security.
“In Africa, people do not use fertilizers Because they have no money, and agricultural explorations are small, not exceeding two to three hectares, ”explained Blumwald in one of the university.
“Imagine-plant crops that stimulate soil bacteria to naturally produce the fertilizer they need. It’s a huge difference! ”, Adds the investigator.
Worldwide, Wheat is the second cereal culture in terms of income and the one that most consumes nitrogen fertilizers, representing about 18% do total.
In 2020, more than 800 million tons of fertilizersaccording to data from the United Nations Food and Agriculture Organization (FAO).
However, Plants only absorb between 30 and 50% of the nitrogen of the fertilizers. The rest dries for watercourses, causing dead zones without oxygen, which suffocate fish and other aquatic species.
Part of excess nitrogen on the soil It is also transformed into nitrous oxidea potent gas with greenhouse effect.
The Solution: Protect the “Fixadora”
Nitrogen fixing bacteria produce an enzyme called nitrogenaseresponsible for fixing the nitrogen. Nitrogenase only exists in these bacteria and only works in low oxygen environments.
Legumes like the beans or pea have structures in the roots, designated noduleswhich offer this protected and oxygen -poor environment to bacteria.
Wheat and most other plants do not form noduleswhich is why farmers resort to nitrogen fertilizers.
“For decades, scientists have tried to develop cereals that produced active nodules in the rootsor colonize them with nitrogen fixing bacteria, without great success. We opted for a different strategy“Explained Blumwald.
“We conclude that The location of bacteria is not the most importantprovided that the fixed nitrogen reaches the plant and is able to use it. ”
The team analyzed 2,800 compounds produced naturally by plants and identified 20 which, in addition to other functions, encouraged bacteria to form biofilms.
Estes Biofilms create a protective layer around bacteria, reducing oxygen and allowing nitrogenase to function. Scientists determined how plants synthesize these compounds and which genes involved.
Subsequently to CRISPR, they genetically modified wheat plants to produce one of these compounds, a flavonoid called apigenina.
Wheat with apigenin levels higher than necessary Free the surplus to the ground through the roots. In the tests performed, Apigenin stimulated soil bacteria to form protective biofilms, allowing nitrogen to fix and assimilation by wheat plants.
Genetically modified wheat plants also presented a productivity superior to control when cultivated with very low levels of azoted fertilizer.
In the US alone, farmers spent almost 2023 30 billion euros In fertilizers, according to estimates by the US Department of Agriculture. Blumwald calculates that almost 200 million hectareof agricultural land in the country are occupied by cereals.
“Imagine saving 10% of the amount of fertilizer used in these lands, ”projects the researcher.“ Even in a conservative estimate, this would represent a Savings exceeding a billion euros Every year, ”he concludes.
