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Researchers at North Carolina State University have discovered that
inserting a specific gene from a bacterial virus into tall fescue grass
makes the grass resistant to two of its biggest enemies, March 2007.

The NC State researchers showed that the inserted gene ? the T4
lysozyme gene, a gene found in bacteriophages, or bacterial viruses ?
conferred high resistance to gray leaf spot disease in six of 13
experimental grasses. Three of the six resistant grasses also showed
high resistance to brown patch disease. These two diseases are arguably
the most important ? and severe ? fungal diseases affecting tall fescue
grass.

The finding has the potential to have wide applications in engineering
resistance to a variety of fungal diseases in not only tall fescue grass
? the most widely planted turfgrass in North Carolina and a commonly
utilized grass in the southeastern United States ? but various other
crops.

A paper describing the study was published in the February edition of
Transgenic Research.

The collaborative research involves four faculty members: Dr. Ron Qu in
the Department of Crop Science, Drs. H. David Shew and Lane Tredway from
the Department of Plant Pathology, and Dr. Eric Miller, in the
Department of Microbiology. The research was mainly performed by Dr.
Shujie Dong, a post-doctoral researcher who was a graduate student of
Qu?s, with assistance from two other scientists in Qu?s lab ? Drs.
Jianli Lu and Elumalai Sivamani.

About half of the turfgrass planted in North Carolina ? one million
acres ? is tall fescue grass, a cool-season grass that has a high
tolerance for the heat and drought of North Carolina summers, Tredway
says. It is ubiquitous in the Southeast, found on lawns, golf courses
and commercial acreages.

Gray leaf spot disease is caused by the Magnaporthe grisea fungus, the
pathogen that also causes rice blast ? the major disease of rice plants.
Gray leaf spot causes round or oval tan spots that turn gray when
there?s high humidity. It infects blades to make the grasses die
rapidly.

Brown patch disease, caused by the soil-dwelling fungus Rhizoctonia
solani, a major pest to various plant species, brings about circular,
brown lesions on grass. Lawns with brown patch disease appear wilted,
even if watered sufficiently, the researchers say.

Miller, the microbiologist, says that the bacterial viruses exist widely
in different environments, and produce an array of products that are
harmful to bacteria; as viruses attempt to spread, which they need to do
in order to survive and thrive, the T4 lysozyme gene produces the
enzymes that chew through the bacterial cell walls.

Miller says that the lysozyme now made by the grass does essentially the
same thing to a fungus when it tries to infect, thereby providing
anti-fungal properties in tall fescue and allowing the grass to
withstand fungal disease.

Tredway says the benefits of potential applications may be felt
economically and environmentally.

?A lot of money is spent on fungicides, which also have an impact on the
environment,? he said. ?Disease-resistant plants have the potential to
reduce those economic and environmental impacts for many years.?

Qu says that future research will replicate this experiment in the
field, rather than just in the lab, and that other disease resistance
genes show anti-fungal properties in tall fescue. He also hopes to study
how the group?s genetically altered plants interact with other important
fungal diseases to further test their anti-fungal mettle.

Much of the work was funded by NC State?s Center for Turfgrass
Environmental Research and Education and the Turfgrass Council of North
Carolina.

[news.ncsu.edu]