Research digs into delicate plant, soil interactions
As the growing season progresses, you might not notice much about what's happening to plants under the soil. Most of us pay attention to new shoots, stems, leaves, and eventually the flowers and crop we intend to grow. We might think of roots as necessary, but uninteresting, parts of the crop production process.
Paul Hallett and his team disagree. They focus on what's going on in the soil with the plant's roots.
The zone of soil that surrounds a plant's roots is called the rhizosphere. It's the combination of the Latin words for "root" and "area." And it's a busy location for important-but hidden-crop production processes.
In the rhizosphere, plants make a variety of chemical compounds called exudates. Hallett and fellow researchers at the University of Aberdeen look at the effects that exudates have on the plant and surrounding soil community. Their unique work takes small-scale measurements near the surface of the roots. The properties here can be very different from the rest of the soil.
"Roots continuously secrete chemicals into the soil as a way to liberate nutrients that are attached to soil particles," says Hallett. In human digestion, the stomach secretes gastric juices to help break up food; exudates are the plant equivalent of gastric juices.
Hallett describes exudates' chemical composition as "a veritable cocktail or 'buffet' of resources for anything in the rhizosphere." In addition to helping plants procure nutrients, exudates are food sources for the microbes that are an important part of the soil microbiome.
Exudates also have an important role in holding soil together. Roots and fungi that live in the soil hold together larger clumps of soil, but exudates work on the micro level. Like glue, they hold together soil particles in important mechanical networks. Soil scientists call these soil networks aggregates.
Whereas the binding effects of roots and fungal networks are usually long-term, exudates' influence on the soil can be fleeting. "Root exudates won't last in their original form for long in the soil, as they get consumed and transformed by microbes," says Hallett. This process can completely destroy the exudate or create even better compounds for binding soil particles.
"Plant root exudates have a massive impact on aggregate formation," says Hallett. "They do this through a number of ways, including acting like glues or changing how quickly the rhizosphere wets up and dries with rainfall and evaporation."
Hallett's team researched the effects of exudates on different types of soil. They researched environments with a sandy loam soil texture versus a clay loam texture. This is important because chemical reactions between the exudates and soil particles vary with soil type.
They also researched various plant exudates from barley and corn. They found that barley's exudates increased how well soil particles are bound together, but not as much as corn. They also found that while barley exudates didn't impact soil water repellency, corn exudates did.
Research such as Hallett's shows that during the growing season-and beyond-there are delicate interactions between each plant and the surrounding soil. All of these interactions affect the amount of water that is captured by soil and absorbed by plants. Production of exudates also affects how well the plants can pull vital nutrients out of the soil, and even affects the soil in the rhizosphere.
Future research for Hallett's team will include looking at exudate production along plants' roots. They'll also look at the age of roots, and whether younger roots produce exudates with different soil-holding and water-absorbing qualities.
Read more about Hallett's research in Vadose Zone Journal. Funding for this project came from the Biotechnology and Biological Sciences Research Council (BBSRC) project 'Rhizosphere by Design' (BB/L026058/1, BB/J000868/1, and BB/J011460/1).
Susan Fisk | EurekAlert!
Geochemists measure new composition of Earth’s mantle
17.09.2019 | Westfälische Wilhelms-Universität Münster
Low sea-ice cover in the Arctic
13.09.2019 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
How long the battery of your phone or computer lasts depends on how many lithium ions can be stored in the battery's negative electrode material. If the battery runs out of these ions, it can't generate an electrical current to run a device and ultimately fails.
Materials with a higher lithium ion storage capacity are either too heavy or the wrong shape to replace graphite, the electrode material currently used in...
To process information, photons must interact. However, these tiny packets of light want nothing to do with each other, each passing by without altering the...
Researchers from the Department of Atomically Resolved Dynamics of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg, the University of Hamburg and the European Molecular Biology Laboratory (EMBL) outstation in the city have developed a new method to watch biomolecules at work. This method dramatically simplifies starting enzymatic reactions by mixing a cocktail of small amounts of liquids with protein crystals. Determination of the protein structures at different times after mixing can be assembled into a time-lapse sequence that shows the molecular foundations of biology.
The functions of biomolecules are determined by their motions and structural changes. Yet it is a formidable challenge to understand these dynamic motions.
At the International Symposium on Automotive Lighting 2019 (ISAL) in Darmstadt from September 23 to 25, 2019, the Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, a provider of research and development services in the field of organic electronics, will present OLED light strips of any length with additional functionalities for the first time at booth no. 37.
Almost everyone is familiar with light strips for interior design. LED strips are available by the metre in DIY stores around the corner and are just as often...
Later during this century, around 2060, a paradigm shift in global energy consumption is expected: we will spend more energy for cooling than for heating....
19.09.2019 | Event News
10.09.2019 | Event News
04.09.2019 | Event News
20.09.2019 | Life Sciences
20.09.2019 | Life Sciences
20.09.2019 | Life Sciences