Versatile compound examined in crops

August 2, 2011

Detergent-like compounds called saponins are best known for their cleansing properties, but U.S. Department of Agriculture (USDA) scientists are studying these compounds' potential for helping protect plants from insect attack.

In studies at the National Center for Agricultural Utilization Research, operated in Peoria, Ill., by the Agricultural Research Service (ARS), scientists Pat Dowd, Mark Berhow and Eric Johnson are "spiking" laboratory diets fed to earworms and fall armyworms with saponins from soybeans, switchgrass, yerba mate and other sources to determine exactly what effects the compounds have on the caterpillar pests' growth and survival. ARS is USDA's principal intramural scientific research agency.

The saponin experiments are part of a broader research effort at Peoria to identify novel sources of resistance that can be incorporated into corn. Ultimately, this could usher in new corn varieties that sustain less caterpillar feeding damage, are less prone to toxic molds or require fewer pesticide applications.

Most grain crops, including corn, don't have saponins in them, according to Dowd, with the center's Crop Bioprotection Research Unit. However, ongoing studies of switchgrass, a distant relative, may reveal dormant genes or biochemical pathways that could be activated in corn using or genetic engineering methods.

One lead the Peoria researchers are investigating came from geneticist Ken Vogel and his colleagues at the ARS Grain, Forage and Bioenergy Research Unit in Lincoln, Neb. In studies there, Vogel's team identified two saponins in switchgrass a steroidal type called diosgenin, and a related form called protodioscin that they suspect helped several germplasm lines of the promising biofuel crop resist fall armyworms.

Dowd's team conducted follow-up experiments in which diosgenin and protodioscin were fed to the pests and compared to saponins from mate, soap bark tree and soybeans and other sources. Protodioscin, like the others, showed activity against fall armyworms, but the most effective ones seemed to be those containing a sugar molecule. Soyasaponin B, for example, reduced the growth of corn earworms by more than 50 percent. Smaller caterpillars, in turn, can mean less crop damage and easier pickings by predators.

Explore further: Corn lines resist fungal toxins

Provided by: United States Department of Agriculture - Research, Education and Economics


Related Stories

Corn lines resist fungal toxins

September 3, 2010

( -- Corn germplasm lines developed by U.S. Department of Agriculture (USDA) scientists are scoring high marks in field trials for resistance to aflatoxin produced by Aspergilllus flavus and A. parasiticus fungi.

Cuphea Does Wonders for Wheat and Corn in Rotations

January 11, 2010

( -- Growing the oilseed plant called cuphea the year before growing wheat results in better wheat seedling survival and grain that is 8 percent higher in protein, according to an Agricultural Research Service ...

New Switchgrass Germplasm Collected in Florida

November 26, 2009

( -- Agricultural Research Service (ARS) scientists and cooperators have collected 46 new populations of switchgrass in Florida, adding valuable new accessions to the germplasm collection of this potential bioenergy ...

Advancing biocrop alternatives in the Pacific Northwest

February 3, 2011

Pacific Northwest farmers could someday be filling up their machinery's tanks with fuels produced from their own fields, according to ongoing research by U.S. Department of Agriculture (USDA) scientists.

Improving swine waste fertilizer

July 8, 2008

Swine production generates large amounts of waste. While this waste contains nutrients that may serve as fertilizer when applied to agricultural fields, the ratio of nutrients in the waste is different than what a crop requires.

Seeds of aflatoxin-resistant corn lines available

May 20, 2010

Six new corn inbred lines with resistance to aflatoxin contamination have been found to be free of seed-borne diseases foreign to the United States, and seeds of these lines are now available in the United States for further ...

Recommended for you

Ten months in the air without landing

October 27, 2016

Common swifts are known for their impressive aerial abilities, capturing food and nest material while in flight. Now, by attaching data loggers to the birds, researchers reporting in the Cell Press journal Current Biology ...

Study shows mixed fortunes for Signy penguins

October 27, 2016

A forty year study on a remote Antarctic island shows that while populations of two penguin species are declining, a third is increasing. Analysis of census data from Signy Island in the South Orkney Islands reveals that, ...

How a fungus inhibits the immune system of plants

October 27, 2016

A newly discovered protein from a fungus is able to suppress the innate immune system of plants. This has been reported by research teams from Cologne and Würzburg in the journal Nature Communications.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.