In a document published in the journal Nanomaterials, the scientists explain that modern methods of mass phytoproduction include obtaining planting material from woody plants through in vitro clonal micropropagation. This method of vegetative propagation makes it possible to obtain new plants, genetically identical to the original specimen, in a laboratory container or other controlled experimental environment rather than within a living organism or natural environment.
The technology, however, poses some challenges. As nutrient media for phyto-clones provide ideal conditions for microbial growth, new plants must be created and maintained in complete sterility. Antibiotics are increasingly used to reduce the risk of contamination of plants propagated in vitro.
But in addition to their bactericidal effect, antibiotics can also have a toxic effect on plant tissues and inhibit their growth and development. In addition, microorganisms can adapt to biocidal drugs through mutations, which leads to resistance of plant pathogens.
Enter copper oxide nanoparticles
In the opinion of Russian experts, the use of copper nanoparticles as sterilizing agents can therefore be a safe alternative to antibiotics.
Specifically examining the effects of copper oxide nanoparticles on the growth of spore-forming mold colonies, as well as the production of stress-resistant genes in birch clones in vitro when infected with plant pathogens, the group has found that copper oxide nanoparticles had a pronounced antifungal effect on plant pathogens in plant culture.
“As possible mechanisms of this phenomenon, we hypothesize both the diffusion of copper ions, which is an antimicrobial agent, and specific nanotoxic effects, such as the induction of oxidative stress or damage to the cell membrane” , said Olga Zakharova, one of the researchers of the study. co-authors, said in a press release.
According to Zakharova and her colleagues, maximum plant sterility was observed at the lowest concentration of nanoparticles studied. Thus, it is possible that the effect is obtained not by the direct destruction of phytopathogenic microorganisms by nanoparticles, but indirectly by the stimulation of the immunity of the seedlings.
“Nanoparticles at low concentrations can cause moderate stress in plants, one of the reactions of which is a change in their biochemical status,” Zakharova said. “Compounds such as peroxidases and polyphenols, which are part of the non-specific protection system of plants against phytopathogenic microorganisms, are beginning to be produced. At the same time, an increase in nanoparticle concentration increases nano-induced stress, and the overall efficiency of plant adaptation to stress begins to decrease, which ultimately manifests as a reduced number of micro – Viable clones at maximum concentration. of nanoparticles.
The researcher pointed out that the data they obtained supports the prospect of using copper oxide nanoparticles to optimize in vitro plant cultivation technology.