This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Supplemental material
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Moon, Y.-S.
Right arrow Articles by Churchill, A. C. L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Moon, Y.-S.
Right arrow Articles by Churchill, A. C. L.
Agricola
Right arrow Articles by Moon, Y.-S.
Right arrow Articles by Churchill, A. C. L.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, July 2008, p. 4366-4380, Vol. 74, No. 14
0099-2240/08/$08.00+0     doi:10.1128/AEM.00285-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.

Agrobacterium-Mediated Disruption of a Nonribosomal Peptide Synthetase Gene in the Invertebrate Pathogen Metarhizium anisopliae Reveals a Peptide Spore Factor{triangledown} ,{dagger}

Yong-Sun Moon,1,{ddagger} Bruno G. G. Donzelli,2,§ Stuart B. Krasnoff,2,3,§ Heather McLane,1 Mike H. Griggs,3 Peter Cooke,4 John D. Vandenberg,3 Donna M. Gibson,3 and Alice C. L. Churchill1,2*

Boyce Thompson Institute for Plant Research, Ithaca, New York 14853,1 Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853,2 Biological Integrated Pest Management Research Unit, USDA-ARS, Tower Road, Ithaca, New York 14853,3 Eastern Regional Research Center, USDA-ARS, Wyndmoor, Pennsylvania 190384

Received 2 February 2008/ Accepted 10 May 2008

Numerous secondary metabolites have been isolated from the insect pathogenic fungus Metarhizium anisopliae, but the roles of these compounds as virulence factors in disease development are poorly understood. We targeted for disruption by Agrobacterium tumefaciens-mediated transformation a putative nonribosomal peptide synthetase (NPS) gene, MaNPS1. Four of six gene disruption mutants identified were examined further. Chemical analyses showed the presence of serinocyclins, cyclic heptapeptides, in the extracts of conidia of control strains, whereas the compounds were undetectable in {Delta}Manps1 mutants treated identically or in other developmental stages, suggesting that MaNPS1 encodes a serinocyclin synthetase. Production of the cyclic depsipeptide destruxins, M. anisopliae metabolites also predicted to be synthesized by an NPS, was similar in {Delta}Manps1 mutant and control strains, indicating that MaNPS1 does not contribute to destruxin biosynthesis. Surprisingly, a MaNPS1 fragment detected DNA polymorphisms that correlated with relative destruxin levels produced in vitro, and MaNPS1 was expressed concurrently with in vitro destruxin production. {Delta}Manps1 mutants exhibited in vitro development and responses to external stresses comparable to control strains. No detectable differences in pathogenicity of the {Delta}Manps1 mutants were observed in bioassays against beet armyworm and Colorado potato beetle in comparison to control strains. This is the first report of targeted disruption of a secondary metabolite gene in M. anisopliae, which revealed a novel cyclic peptide spore factor.

* Corresponding author. Mailing address: Department of Plant Pathology and Plant-Microbe Biology, Robert W. Holley Center for Agriculture and Health, Cornell University, Tower Road, Ithaca, NY 14853. Phone: (607) 255-2179. Fax: (607) 255-1132. E-mail: acc7{at}cornell.edu

{triangledown} Published ahead of print on 23 May 2008.

{dagger} Supplemental material for this article may be found at http://aem.asm.org/.

{ddagger} Present address: Department of Horticulture, Yeung Nam University, 214-1 Daedong, Kyungsan City, KyungBuk, South Korea.

§ Present address: Biological Integrated Pest Management Research Unit, USDA-ARS, Tower Road, Ithaca, NY 14853.

Applied and Environmental Microbiology, July 2008, p. 4366-4380, Vol. 74, No. 14
0099-2240/08/$08.00+0     doi:10.1128/AEM.00285-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.





Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»