As plants compete to extend sunlight upward and outward, the roots move underground to obtain water and nutrients.
The investment made by a plant in its root structure is a combination of the volume of its root branches and the way it spreads. They can grow directly or spread horizontally and blend in with neighbors. It all affects how they gather resources to grow.
Scientists at Princeton University have studied the underground life of plants to see if they invest their roots differently when they are planted only when they grow with their neighbors.
“Most people see plants as static organisms, but that’s because they move at a much slower rate than us,” said Ciro Cabal, a graduate student in the Department of Ecology and Evolutionary Biology, who led an international team of researchers.
He said the lack of research has led to the generalization of the concept that competing plants invest too much in their root systems and thus over-exploit soil resources and deplete them.
This “toilet tragedy” may occur, Cabal said, but it is related to the spatial configuration of plant populations.
The group’s models predicted two potential outcomes for root investment when plants share land. In the first result, the surrounding plants work together to separate their root systems to reduce overlap, but as a result, less root structure is achieved compared to growing in a solitary space. In the second result, when a plant senses limited resources on one side due to the presence of a neighbor, it will shorten the root system on that side, but invest more in the roots below the stem.
According to one news story, each plant works to improve its fitness despite the impact that these actions may have on other plants. But if the plants are next to each other, a large investment in the volume of the roots could lead to the depletion of essential resources.
“It is essential for plants to be able to absorb resources from the soil, such as water or mineral foods,” Cabal said. “It is clear that only fine roots can do this, while they are organs for transporting thick lignified roots.”
He said the biology behind root recognition is a fascinating field that is still developing. It is proved that if a root in a piece of land finds another root, it can know whether the other root is its own or not its own, and it can also know whether it belongs to another plant of the same or different species.
“Various stimuli have been suggested to promote this perceptual mechanism, ranging from the emission and detection of biomolecules to the use of electrical signals,” he said. “It is expected that plants that cannot use these recognition mechanisms would have exploitative behavior, which is the main result we have on paper, because that would be the optimal behavior derived from natural selection.”
The researchers grew greenhouse pepper plants individually and in pairs. As the roots of the plants were dyed in different colors, it was clear what the root of that plant was. They calculated the biomass of the root system of each plant and the relationship to the root sprout, when the plants were planted together with neighbors that change the energy and carbon volume placed in the underground and subterranean structures. The number of seeds produced by each plant was the amount of relativity as a measure. The research provided two model solutions, one based on natural selection and the other on root knowledge.
Kabbalah said that in natural selection there were no mechanisms for recognizing one’s own roots.
“Plants only detect a certain amount of resources entering the system in each piece of soil and the speed at which they leave or discharge resources. The plant will adjust the density of its roots to the balance of the two processes of resources entering and leaving the soil and to grow roots at that location in the soil for grazing. If other plants are grazing in the same place, they may not know the plant directly, but they will perceive a higher rate of resource discharge. If the cost of the plant is low, it will generate more roots in response to increased leakage, but if the cost of growing the roots is high, the plant will generate fewer roots by increasing leakage. ”
The second solution required the recognition of active roots between plants and allowed them to make a collective decision to maximize their overall yield. In the study, when pepper plants were planted close to each other, they increased investment in the roots and reduced the length of the roots horizontally to reduce overlap with neighbors. This prevented the “common tragedy” scenario. There was no difference between the total root biomass or the investments made in the roots compared to the growth of the crustal plants, including the seeds produced. However, this is how the work is being applied in crop production.
“The message to bring home farmers and agtech scientists is simple: wild plants can act selfishly, which leads to the tragedy of communes with the least collective plant yield,” Cabal said. “We also created a theoretical solution for plant root distribution to collectively maximize root efficiency in a shared space. This alternative solution is the best behavior for feeding roots that a farmer can dream of. it comes out of all the soils. “
Experiments with peppers have shown that the productivity of agricultural varieties of agricultural crops can be improved. He will have to do more research, specifically targeting each crop of interest. He said the model solutions could be used to calculate the optimal plant density, to help design new crop varieties or to recommend mechanisms for physically mixing the roots.
Carbon sequestration in root structures makes changes to different scenarios, and learning more about carbon will help design strategies to deal with climate change.
“The design of climate change mitigation strategies is inevitably linked to our ability to predict the future,” Cabal said. “We need to develop models of land systems that generate climate forecasts and use these models to test how we predict changes in different scenarios and different scenarios with different natural changes that can occur. “One of them is vegetation, because plants are key players in the movement of carbon in the atmosphere.”
Research can help optimize food production to maximize crop yields, as it will be invaluable to understand how to make good use of underground resources.
The research was published in the journal Science.