Abstract: Bacillus subtilis NCD-2 was an effective bacterial strain to control verticillium wilt of cotton, and could produce antibiotic substances to inhibit the gowth of Verticillium dahliae, the pathogen causing this disease. The wild type of strain NCD-2 was transformed with the plasmid pHV1249 eaning transposon mini-Tn10 by protoplast measure and the trannformants were screened. Through the transposon minagTn10 mediated innertional mutagenesis technique, more than 4 000 mutants were screened. The inhibiting activity of all mutants were evaluated against V. dahliae by inhibiting zone observation, 2 mutants with significantly enhanc and inhibition activity and 4 mutants with signffcantly decreased inhibition activity were obtained. Using gerome walking technique, gene flanking the mini-Tn10 insertion site was cloned from the two mutants with enhanced inhibition activity, respectively. Gene sequences are most similar to the sequence of the fune-tion-unknown gene yvoA of B.subtilis model strain 168(similarity 98%).Genes flanking the minagTn10 insertion site were cloned from the four mutants with decreased inhibition activity, respectively. Gene sequences are most similar to the sequence of the phoP gene of B. subtilis model strain 168(similarity 98%).

Key words: Bacillus subtalis, Transposon mini-Tn10, Genome walking, Vertacillaum dalzae, Two component regulation system

CLC Number: 

• Q78

• S432.42