Crop & Livestock Advances

Bioengineered Plants Foil One of World's Worst Pathogens

Issue

Root-knot nematodes are microscopic, parasitic worms that attack nearly every food and fiber plant grown. Four major species are responsible for about 95 percent of agricultural infestations.

 

So What?

Iowa State University plant pathologists, working with researchers at two other universities, designed a new way to make plants resistant to one of the world's most destructive plant pathogens. The scientists fed the worm a piece of double-stranded RNA to knock out a specific parasitism gene in the nematode, which disrupted the worm's ability to infect plants. The resistance technique works for all four major species of root-knot nematode and has shown no harmful effects on plants.

 

Impact

The research should lead to new strategies to make host plants resistant to nematodes. The research team also has been making progress in a similar project to disrupt parasitism by the soybean cyst nematode, a major threat to soybean yields in Iowa.

 

Contact: Thomas Baum, Plant Pathology, (515) 294-1741, tbaum@iastate.edu

 

Breeding Soybean for Diseases: Pests and Stress Resistance

Issue

Plant breeders at Iowa State are working to improve genetic resistance of soybeans to diseases, pests and stress. Genetic resistance is the most durable, environmentally friendly and self-sustainable means of protecting the soybean, its yield and the economic returns to soybean growers. The search for new and novel genes conferring resistance, and the introduction of those genes in new germplasm and cultivars for public release and the benefit of soybean growers, is an unending process.

 

So What?

This search is of paramount importance because soybean cultivars in the United States possess a narrow genetic base, making the plant vulnerable to pests and other threats.

 

Impact

The research team has produced new germplasm and cultivars that are directly used by seed companies in their breeding programs, and by growers in their commercial operations. The work continues and more public releases are expected in the near future.

 

Contact: Silvia Cianzio, Agronomy, (787) 830-2390, scianzio@iastate.edu

 

Plant Pathologists Detect Crop Diseases from Satellites

Issue

The advance of Asian soybean rust in the United States is being monitored closely, since the disease can have a devastating effect on infected fields.

 

So What?

Iowa State researchers have developed a way to use satellite images to find Asian soybean rust. Using remote sensing, Global Positioning System and Geographical Information System technologies, scientists can measure the green leaf area of soybeans to detect and identify diseases down to the area of a square meter, about 1.2 square yards. Tests conducted last year in South Africa demonstrated the technology.

 

Impact

The way Asian soybean rust spreads in a field helps identify it from other diseases. Researchers envision the technology being used to narrow the search for soybean rust or other diseases. Plant disease detection using satellites would provide the GPS coordinates for spotters on the ground to pinpoint locations to collect field samples for laboratory tests.

 

Contact: Forrest Nutter, Plant Pathology, (515) 294-8737, fwn@iastate.edu

 

Research Sheds Light on Asian Soybean Rust Infection

Issue

The highly infectious Asian soybean rust can devastate a crop. In countries where it is common, the fungus can wipe out 80 percent of yields, depending on environmental conditions and fungicide use.

 

So What?

An extensive analysis of molecular changes that occur while a plant is being infected by the Asian soybean rust fungus reveals new information that could lead to a soybean variety with broad-spectrum resistance. Iowa State plant pathologists led the three-year research project, which is the largest molecular study of the interaction of soybean and Asian soybean rust.

 

Impact

The project pointed the scientists to genes involved in defending the soybean plant, narrowing the field from 37,500 genes to just a few hundred. Now they are studying those genes experimentally to understand their roles in limiting the growth of the pathogen. The data generated by the research team is a significant genomic resource available online for researchers worldwide to access.

 

Contact: Thomas Baum, Plant Pathology, (515) 294-2398, tbaum@iastate.edu

 

Developing Phytophthora Resistance in Soybean

Issue

Soybean suffers from the root and stem rot disease caused by the oomycete pathogen, Phytophthora sojae. In the United States, the estimated annual yield loss from this disease is valued at $300 million. A series of Rps genes confer Phytophthora resistance, and have been utilized in elite soybean lines to fight this serious disease.

 

So What?

Iowa State researchers have isolated a type II metacaspase gene designated GmMcII, which is essential for expression of Phytophthora resistance. The protein encoded by GmMcII is functionally similar to caspases that regulate the cell death process known as apoptosis in animals.

 

Impact

GmMcII regulates the rapid cell suicidal process following Phytophthora sojae infection so the growth of the pathogen is restricted to the infection sites. The discovery is highly significant because GmMcII now will allow researchers to better understand the mechanism of disease resistance in plants.

 

Contact: Madan Bhattacharyya, Agronomy, (515) 294-2505, mbhattac@iastate.edu

 

New Process Separates Soy Protein into High-value Components

Issue

A good way to add value to the corn and soybeans grown on Iowa farms is to find new uses for the harvest.

 

So What?

Scientists in Iowa State University's Center for Crops Utilization Research developed a new process for separating soybean protein into valuable components with high-value applications for foods. The process separates soy protein into substances that are rich in two major components, glycinin and ß-conglycinin. The desirable gelling properties of glycinin are well-suited for nondairy cheese substitutes and processed meat products. The ß-conglycinin has solubility properties desired in nondairy milk and soy-based beverages. The ß-conglycinin also is attributed to lowering blood cholesterol levels and reducing the incidence of certain cancers. It contains high concentrations of isoflavones, which are attributed to promoting good bone health and reducing osteoporosis.

 

Impact

The new process yields similar total amounts of protein and solids to those achieved in conventional manufacturing of soy protein. The process recovers a higher yield of the valuable components, which also are more functional than products recovered by alternative processes. Work is underway with a private partner to commercialize the research.

 

Contact: Larry Johnson, Center for Crops Utilization Research, (515) 294-4365, ljohnson@iastate.edu

 

Enzymatic Process for Production of Soy Hydrolysate for Adhesives

Issue

Researchers at Iowa State have worked for years to find ways to use Iowa-grown crops to manufacture new products, with adhesives being a major focus.

 

So What?

Scientists developed a new enzymatic process to produce soy protein hydrolysate from soy protein flour, which can be combined with phenol and urea formaldehyde for wood adhesives. The new process developed is safer and more efficient because it is less time intensive, less heat intensive and uses fewer corrosive chemicals than previous methods. In addition, the variation between batches is minimized, providing a more consistent hydrolysate. The hydrolysate also has a light-cream color which is easier to coat and has no ammonia odor.

 

Impact

The enzymatic method has the potential to produce hydrolysates that can be optimized for specific adhesive formulations by changing the enzymes used. Protein hydrolysis reduces the molecular weight of the formulated adhesive, facilitating wood penetration for stronger bonds and a reduction in viscosity that allows manufacturers to use existing adhesive spray systems.

 

Contact: Larry Johnson, Center for Crops Utilization Research, ljohnson@iastate.edu

 

Growth in Alternative Livestock Housing Linked to ISU Research

Issue

High construction and operating costs for livestock confinement buildings may keep some potential producers out of the industry. The size of confinement buildings also may be larger than some producers desire.

 

So What?

An Iowa State interdisciplinary research team is the leader in studying and developing an alternative livestock housing system known as hoop barns. Much of the science-based information available nationally and internationally on raising pigs in deep-bedded hoop barn production systems comes from Iowa State research.

 

Impact

The ISU scientists have shown hoop barns provide production efficiencies such as average daily gain, feed efficiency and pigs per sow per year comparable to more traditional livestock facilities. They have shown profitability - and meat quality - is comparable with other housing systems. As a result, the swine industry has seen a rapid growth in adoption of hoop barns. Now the researchers are evaluating the production of beef cattle in bedded barns.

 

Contact: Mark Honeyman, Animal Science, (515) 294-4621, honeyman@iastate.edu