Read: a more detailed story about the work in the Agricultural Research.

Bad Virus Put to Good Use in Lab

A plant virus that normally causes disease in wheat crops may actually do some good for a change--as a biotech tool in the laboratory.

The wheat streak mosaic virus (WSMV), spread by wheat curl mites, can cause large crop losses at its worst, like the outbreak which cost Montana growers $35 million in 1995.

Since then, however, an Agricultural Research Service and University of Nebraska team has decoded the genetic secrets behind WSMV’s costly ability to destroy wheat. They have charted all 9,384 of the chemical letters, or nucleotides, comprising the virus’ genetic code. In the process, the researchers identified gaps in the virus’ genetic code where new information could be inserted, such as adding genes for proteins or traits that would actually benefit wheat plants.

ARS plant pathologist Drake Stenger says their approach uses the altered virus as a “vector” for delivering and expressing introduced genes into grown wheat plants. Then they can examine what these viral-borne genes do, and for how long. The scientists can also gauge how these genes will affect plant tissues much more quickly than if they introduced the traits through traditional breeding or even conventional genetic engineering. That could help biotechnologists save time when they screen for genes that control traits like improved nutrition, higher yield, better stress tolerance, or pest resistance, says Stenger, who is at ARS’ Wheat, Sorghum and Forage Research Unit in Lincoln, Nebraska.

So far, the Lincoln team has only modified the virus with two bacterial enzymes for proof-of-concept purposes, but other genetic “payloads” are planned. One goal is discovering proteins that could ultimately help wheat plants inhibit other disease pathogens from replicating. Once perfected, researchers will transfer the technology to commercial wheat breeders, who can then adapt it for engineering new varieties with desirable new traits that might not otherwise be possible through conventional breeding.

A more detailed story about the work appears in the December issue of Agricultural Research, ARS’ monthly publication.

ARS is the U.S. Department of Agriculture’s principal scientific research agency.

Scientific contact: Drake Stenger, ARS Wheat, Sorghum and Forage Research Unit, Lincoln, Neb., phone (402) 472-3166, fax (402) 472-4020, dstenger@unlnotes.unl.edu.