Redesigned Barley Has Potential to Thwart
By Linda McGraw
December 14, 1999
Agricultural Research Service
scientists are seeing spots while redesigning barley using natural
proteins with the potential to thwart a costly disease-causing fungus. Scab,
caused by the fungus Fusarium graminearum, inflicts losses of more than
a billion dollars to barley, wheat, oats, rye, and corn annually.
Seeing spots in plants is a good sign that scientists can target the
expression of genes in a specific area rather than in the whole plant. F.
graminearum begins damaging barley in the leafy area surrounding the barley
ARS molecular biologist
Skadsen in Madison, Wis., has cloned hordothionin, an antifungal protein
gene found inside the barley kernel. Skadsen has demonstrated
hordothionins detrimental effect on the scab fungus. A
postdoctoral scientist working with Skadsen developed a gene promoter, dubbed
D5, to help target expression of hordothionin. This is a necessary step before
inserting the antifungal gene, according to Skadsen.
They attached a green fluorescent protein, called gfp, from a
jellyfish to the D5 promoter. With a gene gun, they blasted the pair into the
leafy area that surrounds the seed. Within a day, they saw hundreds of green
spots, confirming that gfp was being expressed in the target area. Next,
hordothionin will be added in place of the jellyfish gene. Next summer,
transformed barley containing hordothionin will be checked for its ability to
Skadsen discussed these research findings at the 1999 National Fusarium Head
Blight Forum in Sioux Falls, S.Dak., Dec. 6-8. For more information, visit the
web site of the U.S. Wheat and Barley Scab
ARS is the chief scientific research agency of the
U.S. Department of Agriculture.
Scientific contact: Ronald W. Skadsen, ARS
Cereal Crops Research
Unit, 501 Walnut St., Madison, WI 53705, telephone (608) 262-3672, fax
(608) 264-5528, firstname.lastname@example.org.