Plants to help plants
For many years, the Natural Molecules Chemistry Laboratory (LCMN) has focused on the extraction, characterization and valorization of secondary plant metabolites for agronomic applications. Prof. Marie-Laure Fauconnier, effectively assisted since 2022 by Dr. Manon Genva, is working on various aspects of this theme.
The first phase concerns the extraction and fine chemical characterization of plant extracts containing the targeted secondary metabolites. Green chemistry techniques are favored (use of bio-based solvents, hydrodistillation). Numerous extracts have been characterized from both traditional and highly original plant or plant co-products, such as endemic tropical plants. These plant extracts, called essential oils when obtained by hydrodistillation, are then studied for their applications in agronomy with numerous partner laboratories.
In collaboration with Prof. Frédéric Francis (GxABT) and his team, the LCMN is examining the insecticidal properties of these extracts, notably to protect stored foodstuffs, both in Belgium and in Africa (Senegal, Burundi, Congo). Original application methods, such as direct injection of essential oils into the trunk of fruit trees, have been the subject of joint work with Pr Thierry Hance (UCL). Fungicidal and herbicidal properties are being studied jointly with Prof. Haïssam Jijakli (GxABT) and his team, with a particular focus on protecting stored foodstuffs against mycotoxin-producing fungi or certain crop pests, such as potato late blight.
The fungicidal and herbicidal properties of essential oils are being studied to protect stored foodstuffs against certain crop pests, such as potato blight. Photo: Pixabay.
With the help of Dr Azucena Gonzalez Coloma and her team, the Natural Molecules Chemistry Laboratory is observing the nematicidal and eliciting properties of these essential oils. These projects are complemented by work to develop innovative formulations in collaboration with Sandrine Bouquillon from Reims, and to study modes of action on a molecular scale with Magali Deleu's team (FNRS).
These research projects, in which plants are used to protect other plants, provide food for thought:
Should we use agricultural land to produce plants that will be used to protect other plants?
Is it necessary to take plants from the wild, sometimes excessively, to produce essential oils that will be used to formulate biopesticides?
Should wood or another fossil fuel be used to distill plants to produce an essential oil (often in the tropics), itself intended to protect plants grown in temperate environments?
To address these issues, the LCMN is exploring a number of avenues:
- The use of sawmill co-products such as bark as starting plant material (in collaboration with Valbiom) or the use of invasive tropical plants for distillation.
- The use of whole plant parts placed directly in silos rather than essential oils (successfully tested in Senegal and Congo).
- Co-cultivation of essential oil plants in horticultural plots, to protect food plants from insects and then produce essential oil for additional income (in collaboration with ITA and UGB in Senegal).
- The study of allelopathy, whereby cultivated plants produce compounds called allelochemicals which reduce the germination and growth of neighboring weeds (with Dr. C. De Clerck).
- The use of in vitro culture to produce targeted secondary metabolites.
The use of plants to protect other plants, or "botanicals", is a fascinating subject that draws on many disciplines, with potential applications in both North and South. However, there is still a long way to go if we are to gain a detailed understanding of the mechanisms involved and develop sustainable value-adding strategies to replace conventional pesticides with bio-based solutions.
More information
The Laboratory of chemistry of Natural Molecules
Outstanding LCMN studies
Signal, Not Poison-Screening Mint Essential Oils for Weed Control Leads to Horsemint
Essential oil-based bioherbicides: human health risks analysis
Use of Essential Oils and Volatile Compounds as Biological Control Agents
