Scientists investigate intersection of salt, insect stress in soybeans

Armyworms on Soybeans

The Problem

Chlorides, or salts, occur in soils and water sources in many areas of the United States, including much of eastern Arkansas. Soybeans grown in high chloride environments are subject to salt stress that can weaken the plant and reduce yields. At the same time, they are often subject to stress from chewing insects that feed on the plants.

 

The Research

In research supported by the Arkansas Soybean Promotion Board, Division of Agriculture scientists are screening breeding populations of soybeans using genetic tools to identify genetic markers that can assist plant breeders in identifying breeding lines with salt tolerance. Those can then be incorporated into the Arkansas breeding program to develop salt-tolerant soybean cultivars. But soybeans in the field often experience multiple stresses at the same time.

Ken Korth, a Division of Agriculture plant pathologist, has long investigated the genetics of how plants defend themselves against chewing insect pests. Korth has conducted genetic research that shows even low levels of salt stress can suppress the genetic expressions associated with plant defenses against insects. Even some plants that can tolerate salt stress in most environments may become more susceptible to insect stress, Korth says.

Korth is now working to discover the genetic mechanisms at work in the intersection of plant and insect stresses. He works with the soybean breeding program to develop improved varieties with salt tolerance. His goal is to identify soybean genomes that maintain their ability to defend against chewing insects even under salt stress and to discover the genetic markers associated with those traits.

 

The Bottom Line

Understanding the genetics that control plant response to stress can help identify soybean genomes adept at defending themselves against multiple stresses, like salt and chewing insects. Those traits can then be moved into breeding stock by conventional breeding methods and used to develop improved cultivars.

 

The Researcher

Ken L. Korth

Ken L. Korth

Professor of Plant Biotechnology in the Department of Plant Pathology since 1999.

Korth earned his bachelor’s degree in biological science from the University of Nebraska-Lincoln and his Ph.D. in genetics from North Carolina State University. He is an expert in molecular plant-insect interactions, pathogen and insect resistance pathways, and cellular control of enzymes involved in isoprenoid metabolism. His research uses the tools of molecular biology to examine how plants respond to insect herbivory and insect-derived factors.