The green leaves of plants use the energy of sunlight to make sugar by combining water with carbon dioxide from the atmosphere. This sugar fuels the plant’s growth, but scientists in the University’s Department of Biology discovered that some of it goes straight to the roots to feed a surprising variety of microbes.
A study led by Professor Peter Young, of the Department of Biology at York and Dr Philippe Vandenkoornhuyse of the University of Rennes in France is published in the latest issue of the Proceedings of the National Academy of Sciences of the USA (PNAS).
In the carbon cycle, plants remove carbon dioxide (a greenhouse gas) from the atmosphere. Eventually, the carbon compounds that plants make are “eaten” by microbes and animals, which release carbon dioxide back into the atmosphere. The rapid cycling demonstrated by the new research is an important link in this process.
Professor Young said: “Our research identifies microbes in roots that create a short cut in the carbon cycle. This is an important development given current interest in reducing outputs of carbon dioxide and the ‘carbon trading’ that is intended to help this.”
The researchers traced the path of the carbon by replacing the normal carbon dioxide in the air around the plants with a version made with C-13, a natural, non-radioactive form of carbon that is slightly heavier than the usual kind. Within hours, microbes in the roots were feeding on sugars laden with C-13 and using it to build their own cells.
The newly-made molecules of DNA and RNA produced by the microbes could be separated from pre-existing ones because the C13 made them heavier. DNA and RNA are large molecules that carry genetic information about the organisms that made them, so it was possible to identify the microbes that made those heavy molecules. These were the “greedy” ones that were consuming the largest share of the sugars provided by the plant.
Professor Young said: “There are rich communities of microbes growing in or around the roots of all plants growing in normal soil. Most do no harm to the plant, and some are very beneficial to it. We looked at two sorts of microbe: bacteria and mycorrhizal fungi.”
The researchers found a high diversity of both types of microbe inside the roots of grass or clover plants growing in a pasture, but the “heavy” label revealed that some of these were growing much more actively than others.
Professor Young added: “It is these active organisms that are important because they are turning sugar back into carbon dioxide, which is released into the atmosphere. We were astonished at the wide variety of active bacteria that we discovered. Many of them had not been seen in plant roots before, and we have no idea how they may affect plant growth.”
The role of mycorrhizal fungi is better known. They are particularly important in carbon cycling, because they pump the carbon compounds out of the root into a massive network of fine fungal filaments in the soil, where it becomes available to other microbes and also to larger soil organisms like worms, mites and insects. In return, the fungus gathers phosphorus from the soil and delivers it to the plant, helping the plant to grow better. The research confirmed that there were many different fungi in the roots of each plant, but revealed, for the first time, which of these fungi were most active.
David Garner | alfa
Finding plastic litter from afar
19.11.2018 | Carl von Ossietzky-Universität Oldenburg
Despite government claims, orangutan populations have not increased. Call for better monitoring
06.11.2018 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
19.11.2018 | Event News
09.11.2018 | Event News
06.11.2018 | Event News
19.11.2018 | Materials Sciences
19.11.2018 | Information Technology
19.11.2018 | Life Sciences