Toxins active against pests

Details Toxins active against pests Toxins active against pests

2000-06-30

2003-03-18

Carlson, Karen Cochrane (Department: 1653)

Organic compounds -- part of the class 532-570 series

Organic compounds

Carbohydrates or derivatives

C536S023100, C435S252300

Reexamination Certificate

active

06534644

ABSTRACT:

BACKGROUND OF THE INVENTION
The soil microbe
Bacillus thuringiensis
(B.t.) is a Gram-positive, spore-forming bacterium traditionally characterized by parasporal crystalline protein inclusions. These inclusions often appear microscopically as distinctively shaped crystals. The proteins can be highly toxic to pests and specific in their toxic activity. Certain B.t. toxin genes have been isolated and sequenced, and recombinant DNA-based B.t. products have been produced and approved for use. In addition, with the use of genetic engineering techniques, new approaches for delivering B.t. toxins to agricultural environments are under development, including the use of plants genetically engineered with endotoxin genes for insect resistance and the use of stabilized intact microbial cells as B.t. toxin delivery vehicles (Gaertner, F. H., L. Kim [1988
] TIBTECH
6:S4-S7; Beegle, C. C., T. Yamamoto, “History of
Bacillus thuringiensis
Berliner research and development,”
Can. Ent.
124:587-616). Thus, isolated B.t. toxin genes are becoming commercially valuable.
Until the last fifteen years, commercial use of B.t. pesticides has been largely restricted to a narrow range of lepidopteran (caterpillar) pests. Preparations of the spores and crystals of
B. thuringiensis
subsp.
kurstaki
have been used for many years as commercial insecticides for lepidopteran pests. For example,
B. thuringiensis
var.
kurstaki
HD-1 produces a crystalline &dgr;-endotoxin which is toxic to the larvae of a number of lepidopteran insects.
Investigators have now discovered B.t. pesticides with specificities for a much broader range of pests. For example, other species of B.t., namely israelensis and morrisoni (a.k.a. tenebrionis, a.k.a. B.t. M-7, a.k.a. B.t. san diego), have been used commercially to control insects of the orders Diptera and Coleoptera, respectively (Gaertner, F. H. [1989] “Cellular Delivery Systems for Insecticidal Proteins: Living and Non-Living Microorganisms,” in
Controlled Delivery of Crop Protection Agents,
R. M. Wilkins, ed., Taylor and Francis, New York and London, 1990, pp. 245-255). See also Couch, T. L. (1980) “Mosquito Pathogenicity of
Bacillus thuringiensis
var.
israelensis,” Developments in Industrial Microbiology
22:61-76; and Beegle, C. C. (1978). “Use of Entomogenous Bacteria in Agroecosystems,”
Developments in Industrial Microbiology
20:97-104. Krieg, A., A. M. Huger, G. A. Langenbruch, W. Schnetter (1983)
Z. ang. Ent.
96:500-508 describe
Bacillus thuringiensis
var.
tenebrionis,
which is reportedly active against two beetles in the order Coleoptera. These are the Colorado potato beetle,
Leptinotarsa decemlineata,
and
Agelastica alni.
More recently, new subspecies of B.t. have been identified, and genes responsible for active &dgr;-endotoxin proteins have been isolated (Höfte, H., H. R. Whiteley [1989
] Microbiological Reviews
52(2):242-255). Höfte and Whiteley classified B.t. crystal protein genes into four major classes. The classes were CryI (Lepidoptera-specific), CryII (Lepidoptera- and Diptera-specific), CryIII (Coleoptera-specific), and CryIV (Diptera-specific). The discovery of strains specifically toxic to other pests has been reported (Feitelson, J. S., J. Payne, L. Kim [1992
] Bio/Technology
10:271-275). CryV has been proposed to designate a class of toxin genes that are nematode-specific. Lambert et al. (Lambert, B., L. Buysse, C. Decock, S. Jansens, C. Piens, B. Saey, J. Seurinck, K. van Audenhove, J. Van Rie, A. Van Vliet, M. Peferoen [1996
] Appl. Environ. Microbiol.
62(1):80-86) describe the characterization of a Cry9 toxin active against lepidopterans. Published PCT applications WO 94/05771 and WO 94/24264 also describe B.t. isolates active against lepidopteran pests. Gleave et al. ([1991
] JGM
138:55-62), Shevelev et al. ([1993
] FEBS Lett.
336:79-82), and Smulevitch et al. ([1991
] FEBS Lett.
293:25-26) also describe B.t. toxins. Many other classes of B.t. genes have now been identified.
The cloning and expression of a B.t. crystal protein gene in
Escherichia coli
has been described in the published literature (Schnepf, H. E., H. R. Whiteley [1981
] Proc. Natl. Acad. Sci. USA
78:2893-2897). U.S. Pat. No. 4,448,885 and U.S. Pat. No. 4,467,036 both disclose the expression of B.t. crystal protein in
E. coli.
U.S. Pat. Nos. 4,990,332; 5,039,523; 5,126,133; 5,164,180; and 5,169,629 are among those which disclose B.t. toxins having activity against lepidopterans. PCT application WO 96/05314 discloses PS86W1, PS86V1, and other B.t. isolates active against lepidopteran pests. The PCT patent applications published as WO 94/24264 and WO 94/05771 describe B.t. isolates and toxins active against lepidopteran pests. B.t. proteins with activity against members of the family Noctuidae are described by Lambert et al., supra. U.S. Pat. Nos. 4,797,276 and 4,853,331 disclose
B. thuringiensis
strain
tenebrionis
which can be used to control coleopteran pests in various environments. U.S. Pat. No. 4,918,006 discloses B.t. toxins having activity against dipterans. U.S. Pat. No. 5,151,363 and U.S. Pat. No. 4,948,734 disclose certain isolates of B.t. which have activity against nematodes. Other U.S. patents which disclose activity against nematodes include 5,093,120; 5,236,843; 5,262,399; 5,270,448; 5,281,530; 5,322,932; 5,350,577; 5,426,049; and 5,439,881.
A cry2Aa gene from HD263 kurstaki is disclosed by Donovan et al. in 264 JBC 4740 (1989). Another cry2Aa gene and a cry2Ab gene, from HD1 kurstaki, are disclosed by Widner & Whiteley, 171
J. Bac.
965-974 (1989). Another cry2Ab gene from HD1 kurstaki is disclosed by Dankocsik et al. in 4
Mol. Micro.
2087-2094 (1990). A cry2Ac gene from B.t.S-1 (shanghai) is disclosed by Wu et al. in 81 FEMS 31-36 (1991).
An isolate known as PS192M4 is disclosed in U.S. Pat. No. 5,273,746 as having activity against lice.
The PS86I2 isolate is disclosed in U.S. Pat. No. 5,686,069 as having activity against lepidopterans. PS91C2 is exemplified therein as producing a CryIF(b)-type of lepidopteran-active toxin, the sequence of which is disclosed therein.
Sequence information for a lepidopteran-active toxin from HD525 and the sequence of a lepidopteran-active toxin from HD573 are disclosed in WO 98/00546. Those toxins are not Cry2-type toxins.
As a result of extensive research and investment of resources, other patents have issued for new B.t. isolates and new uses of B.t. isolates. See Feitelson et al., supra, for a review. However, the discovery of new B.t. isolates and new uses of known B.t. isolates remains an empirical, unpredictable art. U.S. Pat. No. 5,506,099 describes methods for identifying unknown B.t. isolates. U.S. Pat. No.. 5,204,237 describes specific and universal probes for the isolation of B.t. toxin genes. These patents, however, do not describe the probes and primers of the subject invention.
BRIEF SUMMARY OF THE INVENTION
The subject invention concerns materials and methods useful in the control of non-mammalian pests and, particularly, plant pests. In a specific embodiment, the subject invention provides new toxins useful for the control of lepidopterans. A preferred embodiment of the subject invention further provides nucleotide sequences which encode the novel lepidopteran-active toxins of the subject invention.
The subject invention further provides nucleotide sequences and methods useful in the identification and characterization of novel genes which encode pesticidal toxins. In one embodiment, the subject invention concerns unique nucleotide sequences which are useful as primers in PCR techniques. The primers produce characteristic gene fragments which can be used in the identification and isolation of novel toxin genes. A further aspect of the subject invention is the use of the disclosed nucleotide sequences as probes to detect genes encoding B.t. toxins which are active against lepidopterans.
Further aspects of the subject invention include other novel genes and toxins identified using the meth

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