Secret lives of corn plants: filmed “on camera”

The secret life of corn plants: filmed “on camera”

Corn is a seemingly simple plant, but underground it has a very complicated life.

When scientists develop environmental and climate computer models, they take into account a wide variety of processes, such as photosynthesis, respiration rates, soil conditions, carbon distribution, nutrient extraction, rates of decomposition of litter – and this only concerns plants. Yet despite decades of scientific study and modeling, the dynamics of underground plant roots are a ‘black box’ because quantifying how water and nutrients from the soil pass from plant roots to plants. he microscopic scale has remained elusive.

Therefore, details on the dynamic functions of roots are mostly missing from terrestrial biosphere models, or are greatly simplified by using fixed parameters. However, root activity has been shown to be highly variable and has substantial impacts on soil properties including water retention, water flow, and uptake of nutrients, chemicals and soil. pollutants in the soil. Capturing root dynamics and their impacts on soil moisture “on camera” in 3D and in real time would allow better representation of roots for modeling.

To facilitate the study and understanding of root activity, scientists are using neutrons to develop new methods of neutron imaging in the High Flux Isotope Reactor (HFIR) located at the Department’s Oak Ridge National Laboratory (ORNL). of Energy (DOE). Neutrons are highly penetrating, non-destructive properties that sweep sandy soil, which, together with new algorithms (sequences of instructions telling a computer what to do), allowed researchers to capture neutron CT images of roots faster while observing them for longer periods. time to accurately record root activity in real time.

“Neutron computed tomography, or CT, uses neutrons to look inside objects without opening them, much like X-ray CT scans used in medical applications,” said Jeff Warren, senior scientist at the ORNL Environmental Sciences Division. “Applying conventional CT methods directly to image objects that change during a scan can be extremely difficult. This is why we are developing algorithms that collect data much faster, as well as algorithms to capture full images of root dynamics, which will help further research to reduce uncertainty in future models of the terrestrial biosphere. .

Jeff Warren injecting water into the roots

Jeff Warren of the HFIR Imaging beamline injects water into a quartz cylinder filled with a sand-clay soil mixture to assess the 3D dynamics of water uptake in plant roots of corn. Credit: ORNL / Geneviève Martin

New, non-invasive scanning techniques are needed, as direct physical sampling of soil and root water can damage the rhizosphere (the area around the roots of plants inhabited by a unique system of microorganisms) and the xylem (plant vascular tissue that conducts water and dissolved nutrients from the roots), causing misinterpretations of root function data. Installing soil or plant water sensors is equally invasive and only captures bulk data at single points that do not relate water uptake to individual characteristics of the roots. Despite the difficult nature of data collection, the algorithms developed at ORNL are powerful enough to be able to accurately reconstruct an object in real time.

“We are also developing algorithms based on artificial intelligence to obtain high fidelity images, an increasingly popular technique in the field of computed tomography,” said Singanallur “Venkat” Venkatakrishnan, researcher at the ORNL Electrical and Electronic Systems Research Division. “We are training machine learning models to produce higher quality images of root structures and activity from extremely complex CT data in a fraction of the time typically required by more complex methods. “

Venkat on the computer screen

Singanallur “Venkat” Venkatakrishnan helped develop an algorithm to obtain rapid real-time CT images of complex plant root systems and their functions. Credit: ORNL / Geneviève Martin

“One of our goals was to visualize in 3D how fast water moves through the soil and is absorbed into the roots, which was previously limited to visualizing 2D images of roots compressed between thin plates,” a said Warren. “HFIR’s neutron imaging facility helped us observe and record the absorption process in 0.1-10 second exposures to capture real-time water absorption instead of just taking individual snapshots. “

The new, faster experiments produced over 2 terabytes of data (over 160,000 high resolution images). The CT reconstructions from the data will be compared to independent models of soil water flow to validate and refine representations of 3D water flow between soils and roots. The results can be used to inform the development of more advanced terrestrial biosphere models that include soil hydraulics, a current priority for the DOE Office of Science.

The initial success of using fast neutron computed tomography to obtain high resolution images of root functions is encouraging. This technique could potentially be used to capture whole root scans in less than 10 minutes – and possibly in less than 90 seconds per scan – to dramatically improve the temporal resolution of the HFIR imaging instrument.

The project was supported by the DOE Office of Science.

Waiting for the second target station. ORNL’s Second Target Station (STS) will provide transformative new capabilities for discovery science, enabling breakthroughs in many areas of materials research and development. One of the first STS instruments, CUPI2D, will significantly increase research capabilities in experiments with natural materials, such as corn plants used in CT scans.

CUPI2D, will dramatically improve the capability of imaging dynamic processes in natural and man-made materials, including scientific studies of energy storage and conversion (e.g. batteries and fuel cells), engineering of materials (eg, additive manufacturing and advanced superalloys), nuclear materials (eg, new fuel coatings and moderators), biology and ecosystems, and medical and dental applications.

/ Public distribution. This material is from the original organization / authors and may be ad hoc in nature, edited for clarity, style and length. The views and opinions expressed are those of the author (s). See it in full here.

About Lucille Thompson

Check Also

John Burnside: Every day the natural world reveals its intelligence, but humans choose to ignore it

As a child, I was taught to believe that, unlike humans, animals were not intelligent …

Leave a Reply

Your email address will not be published.