In search of a stress buster for plants

There are various ways we deal with stress, whether it's resting, taking a stroll, indulging in comfort food, reading a good book, or hitting the gym. Despite our individual coping mechanisms, one thing remains consistent - the stress response is universally shared at the cellular level between animals and plants. Despite this common element, there is one big difference between plants and animals.

When it is too hot outside, animals will look for the shade of a tree, and when it is too cold, they will seek refuge in their warm dens. However, plants are sessile organisms, which means they are anchored to the soil and thus cannot escape from stressful situations.

Biotic stresses from bacterial, fungal, and viral pathogens, as well as abiotic stresses from extreme temperatures, droughts, floods, excessive salinity, and variations in exposure to sunlight, are all challenges that plants encounter daily in the wild.
Now a team of researchers from the Plant Molecular Farming group within the Environmental Research and Innovation (ERIN) department at LIST have co-authored a study, entitled "Nanoporous Quercetin-Loaded Silicon-Stabilized Hybrid Lipid Nanoparticles Alleviate Salt Stress in Tomato Plants", along with scientists from SiSaf Ltd, a biotech company headquartered in Guildford, UK, putting forward an innovative solution that can protect plants from potential external stress.

The right technology and the right vehicle

The collaboration between LIST and SiSaf is part of a BRIDGES project called Sapphyre, financed by the Fonds National de la Recherche (FNR). The project investigates the effectiveness of SiSaf’s patented silicon-based hybrid lipid nanoparticles in providing plants with quercetin, an antioxidant, known to provide protection from stress.

While silicon is not essential for plant growth, its provision in the form of silicic acid has been shown to have beneficial effects on plants’ response to stress conditions. SiSaf's patented nanotechnology is designed to deliver chemicals to plant cells in a more effective way than traditional spraying methods. The technology uses silicon nanoparticles along with lipids and amino acids to create a micro-cage that can shuttle chemicals into plant cells.

“The idea for the project came about from previous research at LIST on the role of silicon in protecting plants against external stresses,” said Gea Guerriero, co-author. “In the previous study published in the high-impact ACS Nano journal, we tested the technology on Cannabis plants exposed to salt stress. The results showed that spraying the leaves with the technology, which encapsulated the antioxidant quercetin, helped protect the plants from salt stress.”

The present study, published in the ACS Applied Nano Materials journal, aimed to expand on this research by testing the technology on tomatoes, an industrially relevant crop. The results indicate that the technology is indeed effective in protecting tomato plants from salt stress, as evidenced by the preservation of tissue integrity and maintenance of the normal architecture of the leaves. Thanks to the collaboration with the BEAP team, the use of proteomics approaches provided a detailed understanding of the mechanisms underlying the protective effects of the technology on the plant tissues.

Significant implications for agriculture and farming practices

The unique aspect of SiSaf technology is that the nanoparticles are completely biocompatible with plants and are non-toxic. This means that the nanoparticles dissolve over time and release their cargo along with silicic acid, without triggering any toxic effects in the plant. This double-positive effect (release of silicic acid and quercetin) is a unique feature of this technology and has not been reported in the literature before.

“The use of silicon-based nanoparticles as a means of protecting plants against various stresses is a unique and promising area of research,” concluded Guerriero. “While the technology is currently expensive, its potential benefits for crop protection and growth make it a technology worth exploring further. With continued research and development, this technology could have a significant impact on the agricultural sector and help ensure sustainable and healthy crop production in the future.”
Suzanne Saffie-Siebert, CEO of SiSaf, commented: “While we developed our silicon-stabilized hybrid lipid nanoparticles for the stabilization and delivery of drug molecules and SiSaf’s focus is on RNA delivery and therapeutics, we are always open to exploring the potential of the technology for other applications. The work by the LIST team provides compelling evidence that silicon-stabilized lipid nanoparticles could play an important role in the agritech sector.”

The article is co-authored by Gea Guerriero (LIST), Flavia Maria Sutera (SiSaf Ltd.), Jonas Hoffmann (LIST), Céline C. Leclercq (LIST), Sébastien Planchon (LIST), Roberto Berni (LIST), Jean-Francois Hausman (LIST), Jenny Renaut (LIST), Nissim Torabi-Pour (SiSaf Ltd.), Holly Cherise Pennington (SiSaf Ltd.), Mukhtar Ahmed (SiSaf Ltd.), Michael Welsh (SiSaf Ltd.), Ashkan Dehsorkhi (SiSaf Ltd.) and Suzanne Saffie-Siebert (SiSaf Ltd.).