VU LSC Botanist: How Can Plants Help Detect Bombs and Missing People?

A modern person sees the long-lasting, several hundred-million-year dominance of plants on earth as a normal form of life and is not too interested. However, looking at plants from a futuristic perspective, we could discover limitless possibilities for new applications and research, according to a scientist at Vilnius University Life Sciences Centre (VU LSC) Dr Radvilė Rimgailė-Voicik. On the VU podcast Mokslas be pamokslų, the scientists talked about how plants could help detect bombs and even the bodies of missing people if they were researched more.

The importance of plants is underestimated

According to the VU LSC scientist, human adaptation to survival and the specificity of brain activity have led us to pay more attention to animals than to plants. Over a long evolution period, a man has adapted to conditions that required active defense and response, and plants have never been a threatening object.

“Plants are mostly valued from an economic point of view, they are important as a raw material, as food, but not as an object of research. However, we rarely ponder that without plants, there would be no land at all, no soil that also affected the existence of the human genus, which dates back about 6 million years, when the first plants appeared on land about 450 million years ago,” Dr. R. Rimgailė-Voicik said.

According to the VU LSC botanist, living in the anthropocene today, when the world is dominated by humans, we pay too little attention to other life forms, especially plants: “They co-exist with us, only because of the plants we have enough resources to breathe, a gaseous composition of the atmosphere, a stable state of our environment. But from a futuristic point of view, it might be that we’re looking for “aliens” in the wrong area because that linden tree blossoming outside the window may be a very interesting organism with endless possibilities for research and application.”

Can help detect explosives

Dr. R. Rimgailė-Voicik says that research with plants and the possibilities for application are extremely advanced. The Massachusetts Institute of Technology (MIT) has already demonstrated how spinach can react with explosive chemicals and transfer information about it to a computer. This technology is being developed, funded and is especially relevant to the armed forces of large states.

“MIT has begun to develop a new area of research - plant nanobionics - and is using plants to give them futuristic superpowers - to change standard metabolism by introducing a new element. All these experiments involve the use of nanotubes, they are coated with a special polymer and introduced into the cells. That polymer reacts with a substance that scientists want to detect in the environment, such as explosives, changes the fluorescence of the plant, and makes the plant an indicator,” the LSC scientist said.

MIT demonstrated these tests by showing that substances such as nitric oxide can also be detected in this way. However, all these reactions do not occur due to natural parts of the plant but due to mechanically inserted materials, and the changed fluorescence is monitored by additional means, special lighting.

“The plant is illuminated with an infrared chamber, which determines whether the fluorescence of the plant has changed. Currently, the main experiments are with spinach leaves and their fluorescence changes, and the main goal of such studies is to be able to detect as little as possible of the required substance and to perform these studies in real-time. While these are still only futuristic ideas, perhaps someday at the airport we won’t go through screening detectors but through live oases where the screening of human belongings will be determined by the changed color of plant leaves,” the VU researcher said.

Are plants sending us messages?

According to Dr. R. Rimgailė-Voicik, at present, scientists do not yet have an unequivocal answer as to whether a plant is able to distinguish itself from other plants or can distinguish the environment. However, it is well known that plants can release many volatile compounds into the environment around us, which is one of the reasons why this particular form of life has been chosen for research and experimentation.

“More and more research shows that plants release these compounds not only after reaction with sunlight. There are certain distinct “data” that can be used, for example, for a group of certain insects, a progeny grown from seeds of the same plant, or other plant species in they are competing with,” the scientist commented on the latest research data.

According to the VU LSC botanist, there has been a breakthrough in the field of knowledge about mycorrhizal network over the last decade. It is now known that substances released by plants and their concentration can transmit information about the surrounding environment, but the main questions that remain unanswered are related to the wider communication between plants and the ability to process information.

The plants are also adapted to the search for human remains

Another area of research with plants is being conducted at the University of Tennessee. Dr. R. Rimgailė-Voicik says that the scientists working there offer a technology that would be able to detect human remains underground from changes in the forest soil or plants.

“This technology is not yet fully developed and is not yet used, but it is also related to plant fluorescence. In this case, a human does not interfere with the environment and plants, a special apparatus is developed, an unmanned drone that can take high-resolution photos with a special infrared camera, immediately capture changes in fluorescence in plants. This technology is expected to be used in mountains or larger forest massifs to help detect the bodies of missing and dead people,” says the VU scientist.

This technology is especially relevant in countries like the United States, where about 100,000 people disappear without a trace every year. However, it could only be used to detect the bodies and bones of the dead, as changes in the amount of the main photosynthetic pigment, chlorophyll, can only be observed after some time when the nitrogen released by decaying remains is already available to nearby trees. Since such a drone could only record changes in the tops of trees, it would take time for these materials to travel there.

“Scientists have gained experience and already found solutions to a number of shortcomings in similar technologies, such as how to check if a detected body is a human and not, say, a moose or other large animal. Strange as it may seem, food with synthetic additives consumed by humans remains in the tissues, settles as the body breaks down, and leaves a specific fluorescent trace. The same goes for various other substances. For example, traces of heavy metals such as cadmium can be detected in the body of a smoker,” the scientist explains.

Tennessee researchers have found that certain substances leave marks in the human body during long-term observation. A “body farm” was established back in the early 1980s, where the remains of people who have donated their bodies to science give scientists the chance to observe their decay in different media, capture and evaluate the processes that are visible to the naked eye and those that are less obvious. This is how the influence of nitrogen released during decomposition on the greater greenery of plants was observed, and the above-mentioned studies of fluorescent traces began.

Glowing trees to reduce the cost of street lighting

The adaptation of drones requires the cooperation of specialists in many fields - botanists, anthropologists, soil specialists, forensic scientists. According to the researcher, Lithuania has also carried out various research using drones.

“Lidar technology has found the boundaries of old cemeteries and cultural heritage objects in Lithuanian forests - it is important to show that the soil at that site has been disrupted. When it comes to agrotechnology, drones are also used to detect crop phenology, the spread of one or another disease, Dr. R. Rimgailė-Voicik said.

According to VU LSC botanist, although these and similar studies and prepared scientific articles are of the review type so far and stimulate interest in other plant studies, it can be expected that their relevance will only increase in the future. Dr. R. Rimgailė-Voicik is convinced that Lithuania can also foster more active cooperation of scientists in the field of plant research using existing resources, such as a special plant collection at the Lithuanian Forensic Science Center - herbarium, or developing bioluminescent research that would reduce street lighting costs by “enabling” naturally glowing trees.