One of the biggest challenges facing agriculture today is finding a sustainable alternative to the use of fertilisers and pesticides, substances that have a huge impact on the environment. Given the increase in the number of products banned or considered hazardous to human and animal health, there is an increasingly urgent need to find substitutes that are both safe and effective. One of the alternative ways is to stimulate the immune response of plants to pathogen attacks, for example by using silica nanoparticles. Researchers from the Adolphe Merkle Institute and the Department of Biology at the University of Freiburg have synthesised nanoparticles capable of releasing silicic acid, a substance naturally present in soil able to trigger an immune response in plants. They tested these compounds on Arabidopsis thaliana (also known as thale cress) plants infested with the bacterial pest Pseudomonas syringae.
Inflorescence of Arabidopsis thaliana. Credits: Wikimedia Commons
The results showed that their silica nanoparticles are able to increase resistance to bacteria in a dose-dependent manner by stimulating the production of salicylic acid, a plant defence hormone that is also the active ingredient in aspirin. The study, published in the journal Nature Nanotechnology shows that this remedy could be a cheap, highly efficient, safe and sustainable alternative for the protection of plants from pathogens. Future research may extend investigations to a broader spectrum of pathogens such as other bacteria, insects or viruses, according to the scientists. They stress, however, that a thorough analysis is needed before any broad application of these products as biostimulants and fertilisers to assess the potential long-term effects of silica nanoparticles in the environment.