Garden of Words’ is a biodesign project that aims to represent plant communication through a living biosignal / sensor installation.
Plant communicates by using volatile organic compounds, electrical signaling, and common mycorrhizal networks - between plants and a host of other organisms such as soil microbes, other plants (of the same or other species), animals, insects, and fungi. Mycorrhizal networks are underground hyphal network created by mycorrhizal fungis. Through the formation of hyphal networks, individual plants are connected underground and thus; plants are able to transfer water, carbon, nitrogen, other nutrients and minerals to each other. Similar to the World Wide Web that connects the human societies, the role of mycorrhizal network within the underground have been endearly referred (coined by Dr. Suzanne Simard) as the Wood Wide Web.
Mycorrhizal fungis are essential to forest’s health. Trees are affected by increasing abiotic stress linked to climate change such as high temperatures, drought, salt stress, and flooding. Mycorrhizal fungi; through hyphal network alleviate climate change-linked abiotic stress affecting tree growth in temperate and boreal forests by improving plant water and mineral nutrition (among them potassium K+) and helping the trees to adapt to stressful environmental conditions (among them elevated sodium Na+ in saline conditions).
Plant responses to abiotic stress can be determined by the severity of the stress and by the metabolic status of the plant. One of the many chemicals released by the plants when it is undergoing abiotic stress is Abscisic acid (ABA). ABA is a phytohormone critical for plant growth and development and plays an important role in integrating various stress signals and controlling downstream stress responses. Some of the stressors include drought, soil salinity, cold tolerance, freezing tolerance, heat stress and heavy metal ion tolerance. Plants have to adjust ABA levels constantly in response to changing physiological and environmental conditions. If we were to chart the way tree communicates with the Input/Process/Output chart;
| Input | Process | Output |
|---|---|---|
| Abiotic Stressor | Decreased Photosynthetic Activites and Growth Inhibition | ABA |
| Feedback |
|---|
| Other trees send in nutrients through mycorrhizal network to help out the tree under stress |
The way I envision for this biodesign installation to happen is through a 2-3 metre monument with 3D printed fluidic chambers to represent the different chemicals going through the hyphal network. Underneath the installation structure there would be a bioreactor to house the engineered E.coli liquid culture. E.coli is engineered with plant receptors to express the chemical concentration level with chromoproteins. Nutrients + ABA sensors will be placed underneath the soil to record the concentration level of the chemicals. A solar wireless network port will be placed near the designated tree and installation. Through the wireless network, the data from the sensors can be transmitted into the automated valve designed for the bioreactor. The bioreactor will release the chemical concentration based on the transmitted data and the E.coli will react in real time thus allowing the colours to change organically
‘Garden of Words’ is a living biosignal / sensor installation that represents the way trees communicate through the underground mycorrhizal network. The installation utilises next generation synthesis techniques by engineering chemical receptors into E.Coli to sense the concentration of those plant chemicals (ABA, Carbon, Phosphorus, Nitrate) and express the concentration with colour pigmentations (chromoprotein). Through these signals, ‘Garden of Words’ aims to demonstrate the forest’s symbiotic collaboration in the face of climate change whilst also building empathy for visitors to decrease the gap within the human-nature divide.