Have you noticed how plants compete for light? They are stretched outwards to block each other’s rays from entering each other, but out of sight, another kind of competition takes place underground. In the same way that you can change the way you feed free snacks in the break room when your partners are present, the plants change the use of underground resources when they are planted next to other plants.
In an article published today Science:An international team of researchers led by Princeton Iro Iro Kabal is shedding light on the underground life of plants. Their research used a combination of modeling and greenhouse experiments to find out whether plants invest differently in root structures when planted alone or when planted next to seedlings.
“This study was a lot of fun because it combined several different types of mental sweets to reconcile the seemingly contradictory results in the literature. “Smart experience, a new method of observing root systems in inviolable soils – a simple mathematical theory,” said Steven Paclala, Frederick D. Senior author of Petrie պրոֆես Professor of Evolutionary Biology (EEB) էկ.
“Although the surface parts of plants have been extensively studied, including how much carbon they can hold, we know very little about how the underground parts, that is, the roots, hold carbon,” said Kabal, Ph.D. student at Pakala Laboratory. “Because about one-third of the world’s plant biomass is carbon underground, our model provides a valuable tool for predicting root propagation in global models of the terrestrial system.”
Plants form two different types of roots. Fine roots that absorb water from the soil ուցիչ nutrients, և coarse transport roots that transport these substances to the center of the plant. The “introduction” of plants into the roots includes both the total volume of roots produced and the total soil to distribute those roots. The plant could concentrate all its roots directly under the stems, or it could spread its roots horizontally to feed in adjacent soil, which threatens to compete with the roots of neighboring plants.
The team model predicted two possible outcomes of rooting when plants appear to divide the soil. In the first case, the neighboring plants “cooperate” by dividing their root systems to reduce overlap, resulting in generally fewer roots than they would have alone. In the second case, when the plant feels the reduction of resources due to the presence of the plant, it reduces its root system on that side, but invests more roots directly below the root.
Natural selection predicts this second scenario, as each plant acts to increase its own fitness, regardless of how those actions affect other individuals. If plants are too close together, this large contribution of root volume, despite the separation of those roots, can lead to a community tragedy in which resources (in this case, soil moisture ները nutrients) are depleted.
To test the predictions of the model, the researchers grew pepper plants in the greenhouse “individually” in pairs. At the end of the experiment, they painted the roots of the plants in different colors so that they could easily see which plants belonged to which roots. They then calculated the total biomass of each plant’s root system և root և shoot ratio to see if the plants had changed how much energy խ they had filled in the carbon կառույց underground structures when planted next to the neighbors քանակ counted the number of seeds produced. each plant as a measure of relative fitness.
The team found that the result depends on how close a pair of plants are to each other. If planted too close together, the plants are likely to invest heavily in their root systems, trying to outperform each other for finite groundwater resources. If they are planted farther apart, they are less likely to invest in their root systems than a single plant.
In particular, they found that when planted with others, pepper plants locally increase root investment and reduce horizontally stretched roots to reduce overlap with neighbors. There was no evidence of a “community tragedy” scenario, as there was no overall difference in root biomass or relative root contribution compared to surface structures (including the number of seeds produced per plant) for solitary plants. ,
Plants remove carbon dioxide from the atmosphere, inject it into their structures, and one-third of this plant carbon is stored in the roots. Understanding how carbon sequestration is changing in different scenarios can help us more accurately predict carbon sequestration, which in turn can help develop strategies to mitigate climate change. This research can also help optimize food production, as it is useful to understand how to make optimal use of groundwater resources to maximize crop yields.
Reference. “Exploratory Separation of Plant Roots” by Chiro Caballi, Ricardo Martinez-Garcia, Aurora de Castro, Fernando Valladares և Steven W. Pakalai, December 4, 2020 Science:,
DOI: 10.1126 / science.aba9877:
The other co-authors of the paper are Ricardo Martinez-Garcia, a former EEB graduate student who is now a professor at the South American Institute for Basic Research. Aurora de Castro, who worked on the project within the framework of the bachelor’s thesis of the Chair of Biography and Global Change of the National Museum of Natural Sciences of Spain, Associate Professor, Department of Biology, Geology, Physics and Inorganic Chemistry Valyadares.
“Exploratory Separation of Plant Roots”: Siro Cabal, Ricardo Martinez-Garcia, Aurora de Castro, Fernando Valladaras և Steven W. Pakala, appears in the December 4 issue. Science: (DOI: 10.1126 / science.aba9877): He supported this work Princeton University May Scholarship in the Department of Ecology և Evolutionary Biology; Gordon և Betty Moore Foundations (Grant GBMF2550.06); Instituto Serrapilheira (awarded Serra-1911-31200); Sao Paulo Research Foundation (grant ICTP-SAIFR 2016 / 01343-7); Young Progressives Program in Emergent Centers (2019 / 24433-0); Simmons Foundation; Spanish Ministry of Science, Innovation և Universities (COMEDIAS grant CGL2017-83170-R); և Carbon Mitigation Initiative of the Princeton Environmental Institute.