Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: 1/20/2000
Publication Date: N/A
Citation: N/A Interpretive Summary: Each year, the barley, oat and wheat crops are attacked by crop-destroying fungi. For the last seven years, the barley crop in the main US malting barley producing area has been ravaged by a fungus called Fusarium. To counter these problems, we have been attempting to use molecular biology methods to produce barleys that are resistant to attack by fungi. Two proteins, called permatin and hordothionin, were thought to be toxic to fungi, but not to barley plants. Tests with purified samples of these proteins showed that the hordothion was especially toxic to the Fusarium fungus. Using a method that shoots genes into barley tissues, we have produced one mature barley plant that should produce permatin inside the plant and 100 that should produce hordothionin. If these plants do produce the permatin and hordothionin proteins, they may be more resistant to fungal attack than the parent barleys. If so, it may be possible to again grow malting barleys in areas of the country where Fusarium infestations have recently rendered this impossible. The transformed plants can be used by barley breeders to develop commercial malting barleys that may be resistant to the Fusarium fungus. When such resistant lines become available, barley producers in the Red River Valley should again be able to reliably produce barley that will meet the needs of the US brewing industry.
Technical Abstract: The US barley, oat and wheat crops are challenged annually by crop- destroying fungi and our malting barley crop has been ravaged for the last 7 years by the fungus Fusarium. To counter these problems, we have begun efforts to clone and express antifungal proteins in barley. Clones of the thaumatin-like protein permatin and the small, high-cysteine, antimicrobial protein hordothionin have been used to transform barley using the particle bombardment method. From bombardments with the permatin plasmid, three green plants were obtained. All three contained the bar marker gene, but only one contained the permatin gene. Transformation with the hordothionin gene yielded 106 green plantlets, of which 100 were PCR positive for the thionin gene. Permatin produced by yeast and hordothionin purified from barley were tested to ascertain their antifungal activities against Fusarium and the thionin protein was more toxic than permatin.