04.02.2019 change 04.02.2019

Biologists from the University of Warsaw discovered a safe way to combat weeds

Photo: press materials Photo: press materials

Biologists from the University of Warsaw discovered environmentally safe herbicides that effectively fight weeds. Molecules - innovative in terms of chemical structure - have passed toxicological tests.

ACCIDENTAL DISCOVERY

Substances that destroy plants were discovered in a research and development project that had an opposite goal. Dr. Rafał Archacki and Dr. Paweł Siedlecki at the Faculty of Biology of the University of Warsaw were looking for substances that would help in increasing biomass. They chose many regulators of proteins that stimulate plant growth and development processes, and then tested their effects. Biologists managed to find several promising molecules that would be the subject of further work. But some of the tested substances, contrary to the expectations of researchers, instead of stimulating growth, inhibited it or even destroyed plants.

Researchers from the Institute of Experimental Plant Biology tested the effectiveness of discovered herbicidal substances. The effects of new molecules were compared with the reference compound - glufosinate-ammonium, an ingredient of a popular herbicide. According to the scientists, the results are very promising.

"We selected three chemical molecules during the tests. One of them showed higher efficacy than the reference compound and had a wider scope of activity. The effects of using the other two were comparable to glufosinate" - says Dr. Rafał Archacki, quoted in the release published on the University of Warsaw website.

According to the researchers, the effectiveness of the discovered molecules opens the possibility of developing more environmentally friendly herbicides. In the future, such agents could contain smaller amounts of chemical herbicide, which can translate into a lesser burden on the environment.

They add that molecules of similar strength, but different mechanism of action, are also an opportunity to develop new preparations. Considering the growing resistance of weeds to herbicides and common practice of spraying with several preparations, new solutions can be very useful and have commercialisation potential.

FIELD TEST REQUIRED

For now, the new molecules have been tested in laboratory conditions and on several species of plants in greenhouse conditions. Researchers have proven that they are safe for people who use them - they have little effect on the survival of human cells. They are also not toxic to nematodes living in the soil. After preliminary research, the researchers believe that eventually the new substances can be used in agriculture or horticulture.

"Our further research will consist of testing the potency of the new compounds against weeds in combination with additional excipients that are used in currently available agents. Such excipients are designed to further increase the effectiveness of molecules" - says Dr. Rafał Archacki.

Dr. Paweł Siedlecki emphasizes the necessity of in-depth toxicological tests, because not all discovered molecules have been fully researched in this respect. "Regulations that concern safety are very restrictive, so we need to be sure that the discovered substances do not have a negative impact on people and the environment. More data and tests are needed to obtain a complete set of data. In the near future, we will conduct further research on human cells and nematodes using extended variants of tests" - the biologist says.

Biologists, in cooperation with chemists, modify discovered molecules and search for new ones that will be even more effective and at the same time safe. Siedlecki and Archacki explain that even the smallest change of a chemical molecule can have a huge biological effect. It is also impossible to anticipate the effects of introduced changes in advance. Researchers have to choose options intuitively and test them empirically, which takes time. This means carrying out a lot of tests. Therefore, researchers will look for potential investors who could finance them. Field tests and other more detailed studies will be necessary.

Researchers obtained support from the University Technology Transfer Centre (UOTT UW) in the form of a grant for further tests, implemented as part of the Innovation Incubator+ program.

"The three new molecules are not the end of the search for new substances with specific properties. One of the main values of the discovery is the development of a production method for the new substances. The University of Warsaw has created know-how that allows to develop and test many new substances in a relatively short time" - says Dr. Robert Dwiliński, director of UOTT UW. He adds that the agrochemical industry continues to look for new substances because plants develop resistance to the currently used herbicides. In addition, environmental conditions are changing and new legal regulations regarding health and environmental protection are being created.

"For these researchers, it is an attractive market niche that may allow them to create a spin off" - says Dr. Dwiliński.

MARKET POTENTIAL OF THE DISCOVERY

Marek Massalski from UOTT UW explains that after ploughing the soil, a lot of seeds of various plants remain in it, especially seeds of plants considered weeds, and those plants start growing relatively quickly. In order to obtain a high yield, farmers must fight weeds, the growth of which inhibits the growth of crops. Only after spraying the field and waiting for a certain period, during which weeds disappear and the chemistry stops working, sowing takes place. Thanks to herbicides, agricultural production can be profitable.

There are a lot of different available chemical preparations that fight weeds in crops. They can be used in various ways, they can be applied to all plants without exception or selectively. Most of them are preparations offered by global corporations, but products of smaller, local companies are also available.

"Although the range of available products is wide and new ones are being introduced, there are relatively few active substances that have a herbicidal effect. Therefore, research centres around the world are always trying to develop new active substances" - explains Massalski.

He emphasizes that certain molecules have a stronger effect on certain weeds, weaker on others. In practice, using only one herbicide is uncommon. Usually two or more agents are used to protect crops in case one of them does not work. The more they are used, the higher the costs of cultivation. It is also not neutral for the environment.

According to the representatives of UOTT UW, the commercialisation of the new active substance looks promising. One of the reasons for the search for new substances is that the old ones are being withdrawn from the market due to changing regulations. Some formulas that have been used for years turn out to exceed standards and have a negative effect on human health or organisms in the soil.

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