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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Sunflower and Plant Biology Research » Research » Publications at this Location » Publication #120008
Title: A NEW BACILLUS THURINGIENSIS ISOLATE WITH AN UNUSUALLY HIGH ACTIVITY AGAINST THE BANDED SUNFLOWER MOTH

Author
item Bai, Cheng
item Barker, John
item Yi, Shuxia

Submitted to: Proceedings Sunflower Research Workshop
Publication Type: Proceedings
Publication Acceptance Date: 2/1/2001
Publication Date: N/A
Citation: N/A

Interpretive Summary: A new variety of the bacterium commonly known as "Bt" was discovered from sunflower head extracts which was very toxic to the banded sunflower moth, a serious insect pest for cultivated sunflower plants in the Great Plains. Presently, Bt is used as active factors in commercial preparations to kill insect pests. Biochemical analysis revealed that the toxic proteins of new Bt seemed unique, indicating it might contain novel genes producing special proteins which are highly toxic to the moth. It should be considered as a prime candidate for making a bio-pesticide for use in sunflower insect control and for introduction of its gene into the sunflower plants to produce the toxic proteins for controlling the moth pest.

Technical Abstract: A new bacterial isolate (00-50-5) from sunflower head extracts was identified as Bacillus thuringiensis (Bt) according to its morphology. Bt isolate 00-50-5 was highly effective against the banded sunflower moth (BSM), Cochylis hospes larvae. Bioassays showed that the toxicity of 00- 50-5 to BSM larvae was unusually high and resulted in significantly faster mortality than for the standard HD-1-1980. SDS-PAGE gel revealed Isolate 00-50-5 containing several small peptides in addition to the 60-kDa protein. The electrophoretic diagrams of the crystal proteins seemed unique, indicating it might contain novel genes encoding special toxin proteins. To our knowledge, this is the first study to isolate an extremely pathogenic Bt strain from sunflower insect cadavers and sunflower plant extracts to control of BSM. The isolate 00-50-5 should be considered by industry for preparing a biocide and the toxin genes also should be considered an excellent candidate for transferring into the sunflower plant for control of BSM.