In everyday life, we have a tendency to believe that nature is capable of immediate recovery from minor environmental impacts. Researchers at the University of Debrecen, however, have proven scientifically that long-term, latent stress effects do cause serious damage.
Their research examined the relationship between two fundamental processes present in all living organisms with a cell nucleus (eukaryotes), even in humans. One of these processes is the consequence triggered by a family of protein phosphatases. These regulatory enzymes act as conductors, while directing cellular function and cell division. The other process is oxidative stress, which is caused by harmful free radicals that accumulate in the cells.
- Plants have a peculiar antioxidant enzyme system for neutralizing free radicals. In our research project, we intended to figure out how this line of defense and protein phosphatases interact with one another, influencing a plant’s quality of life or its survival- said Tamás Garda, Assistant Professor at the Department of Botany of the Faculty of Science and Technology, University of Debrecen.
The research team conducted its studies on Arabidopsis thaliana (thale cress or rock cress), a popular model organism in molecular biology, under laboratory conditions. The plants were exposed to doses of two substances found in our natural environment. One of these is microcystin-LR, a toxin produced by cyanobacteria, which appears in large quantities in bodies of water during algal blooms caused by nutrient (nitrogen, phosphorus) loading as a result of agricultural fertilization. The other one is called diquat, an extremely aggressive, non-selective contact herbicide. Its use has already been banned in the European Union, but it still poses a threat if used illegally or still present in the environment.
- In our experiments, a two-day exposure was supposed to be considered as long-term treatment, and the findings revealed a fairly surprising and dramatic difference. Although both of the substances were present only in low concentrations, barely visible to the naked eye, they interfered or intervened with cellular life in completely different ways. While the plant cells were able to mobilize the plant’s defenses and regenerate temporarily following an attack by the naturally occurring cyanotoxin, diquat, the synthetic herbicide, literally ‘brought the cells to their knees.’ In the latter case, long-term exposure caused irreversible cell division anomalies in the plants’ roots, which completely prevented recovery- said Tamás Garda.
Although all this is considered basic research, the findings convey a seriously critical ecological message. The seeping of chemicals and fertilizers into soil and surface waters represents a global problem, be it around Lake Balaton or next to the oceans. Moreover, the danger does not stop at the plant level. Since these internal cellular processes are very similar regardless of the organism they occur in, the toxins produced by cyanobacteria are also harmful to fish and humans, potentially causing severe liver damage in the latter.
Tamás Garda underlined that the prestigious Publication Award should be considered a recognition of genuine teamwork, as the entire team of the Plant Cell and Developmental Biology Research Group within the Department of Botany, as well as additional faculty members of the department, contributed to this success together. However, their work does not come to an end here. In the future, the researchers intend to map up the molecular relationship between enzymes and free radicals even more precisely. A more profound understanding of why exactly plants with damaged enzyme systems become vulnerable could bring us closer to developing more resilient crop cultures and varieties in the future.
Press Center - TB