Skip to main content

Knowledge of Nitrogen Transfer Between Plants And Beneficial Fungi Expands



Knowledge Of Nitrogen Transfer Between Plants And Beneficial Fungi Expands

Date:              June 23, 2005, Science Daily

Source::          USDA / Agricultural Research Service

Summary:        New findings show that a beneficial soil fungus plays a large role in nitrogen uptake and                         utilization in most plants.

 


A microscopic view of an arbuscular mycorrhizal fungus growing on a corn root. The round bodies are spores, and the threadlike filaments are hyphae. The substance coating them is glomalin, revealed by a green dye tagged to an antibody against glomalin.
Credit: Photo by Sara Wright

New findings show that a beneficial soil fungus plays a large role in nitrogen uptake and utilization in most plants.

In a recent issue of the journal Nature, Agricultural Research Service (ARS) chemist Philip E. Pfeffer and cooperators report that beneficial arbuscular mycorrhizal (AM) fungi transfer substantial amounts of nitrogen to their plant hosts. A lack of soil nitrogen often limits plant growth.

The studies were conducted by Pfeffer and David Douds at the ARS Eastern Regional Research Center, Wyndmoor, Pa.; Michigan State University scientists headed by Yair Shachar-Hill; and New Mexico State University scientists headed by Peter J. Lammers and including graduate student Manjula Govindarajulu.

AM is the most common type of symbiotic fungus that colonizes the roots of most crop plants. The fungi receive glucose and possibly other organic materials from the plant, while enhancing the plant's ability to take up mineral nutrients, primarily phosphorus.

The scientists previously identified enzymes and genes involved in nitrogen absorption and breakdown in AM fungi, but very little was known about how nitrogen is moved from fungus to plant or in which form nitrogen moves within the fungus. The researchers discovered a novel metabolic pathway in which inorganic nitrogen is taken up by the fungi and incorporated into an amino acid called arginine. This amino acid remains in the fungus until it is broken down and transferred to the plant.

The results show that the symbiotic relationship between mycorrhizal fungi and plants may have a much more significant role in the worldwide nitrogen cycle than previously believed. With this in mind, farmers may benefit from promoting the proliferation of mycorrhizal fungi through diminished fertilizer input, thereby making more efficient use of the nitrogen stores in agricultural soils.

ARS is the U.S. Department of Agriculture's chief scientific research agency.

Story Source:

The above story is based on materials provided by USDA / Agricultural Research Service. Note: Materials may be edited for content and length.

Click This Link To View the original story in Science Daily:   http://www.sciencedaily.com/releases/2005/06/050619193216.htm


Comments

Post a Comment

Popular posts from this blog

Fertilizers formulated for alkaline soils of the Southwest

Recently I was in an Albuquerque retail nursery where a fertilizer was being sold that stated it was formulated for alkaline soils of the Southwest.  It contained high levels of iron and sulfur, plus the N, P and K major nutrients.  Do any of the readers care to comment on this type of product?    Pros, Cons, etc.  I have my take on it, but I'll entertain what you want to say about it.  Michael Martin Meléndrez
9 comments
Read more

Growing Pecan Trees in Western Alkaline Soil

It's common to see nutrient and water inhibition compromise the production of pecans in the arid western states, particularly where the soils are high pH, which can tie up nutrients such as zinc, iron, phosphorus and more. Keeping soils moist is also a problem because the regions were we grow pecan are not wet bottomland soils where pecan is native, but are high and dry desert soils where irrigation is essential. If the irrigation water is high in dissolved solids, the problem is made worse. There are many good things Soil Secrets can offer pecan growers that can overcome these obstacles, by improving the moisture management of the soil, improving nutrient solutioning and availability of both the native minerals as well as the purchased minerals, and improving the porosity of the soil so that water and oxygen can penetrate meters deep without the need to subsoil with machinery. How's this done? By using the power of Nature's own bio-chemical called the Carbon Matrix. Starti
Post a Comment
Read more

Soil Health: Level 2 - Description of Terms (Carbon Compounds)

The  Labile Carbon  is also known as the 'Rapid Cycling Carbon' and its composed of all the Soil Organic Matter that is dead and actively decomposing.  It's benefit to the soil is that it provides a source for minerals that are being recycled as potential plant nutrients, so in a sense it's Nature's fertilizer.  Active Carbon   also known as Reactive Carbon is more complex than the Labile Carbon in that its composed of all the dead and actively decomposing organic matter plus all the living soil microbial community that will eventually die and begin decomposing.   For example, the hyphae of mycorrhizae only live about 5 to 7 days before they die and start to decompose, while the fungus organism itself may live far longer.  Recalcitrant Carbons   are the Humic substances made up of complex organic chemistry, some of which is inert and some of which is very reactive and are powerful biologics, such as the Humic Acids.  Recalcitrant Humic substances are known in la
9 comments
Read more