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Presents a study to address the requirement for any pectin-degrading ability in pathogenesis by Cochliobolus carbonum. Methodology used to conduct study; Indication of findings; Discussion on results.

Describes the structure of a putative cyclic peptide efflux pump encoded by the TOXA gene of the plant-pathogenic fungus Cochliobolos carbonum. Possibility of mutating one copy or the other of TOXA by targeted gene disruption; Cloning and sequencing of TOXA; Presence of TOXA only in Tox isolates; Transformation-mediated gene disruption of TOXA.

Bioassay screening of Bacillus thuringiensis culture supernatants identified strain EG2158 as having larvicidal activity against Colorado potato beetle ( Leptinotarsa decemlineata) larvae. Ion-exchange fractionation of the EG2158 culture supernatant resulted in the identification of a protein designated Sip1A (secreted insecticidal protein) of approximately 38 kDa having activity against Colorado potato beetle (CPB). An oligonucleotide probe based on the N-terminal sequence of the purified Sip1A protein was used to isolate the sip1A gene. The sequence of the Sip1A protein, as deduced from the sequence of the cloned sip1A gene, contained 367 residues (41,492 Da). Recombinant B. thuringiensis and Escherichia coli harboring cloned sip1A produced Sip1A protein which had insecticidal activity against larvae of CPB, southern corn rootworm ( Diabrotica undecimpunctata howardi), and western corn rootworm ( Diabrotica virgifera virgifera). [ABSTRACT FROM AUTHOR]