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 Prados Rosales, R. C.
Right arrow Articles by Di Pietro, A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Prados Rosales, R. C.
Right arrow Articles by Di Pietro, A.

 Previous Article  |  Next Article 

Eukaryotic Cell, January 2008, p. 162-171, Vol. 7, No. 1
1535-9778/08/$08.00+0     doi:10.1128/EC.00258-07
Copyright © 2008, American Society for Microbiology. All Rights Reserved.

Vegetative Hyphal Fusion Is Not Essential for Plant Infection by Fusarium oxysporum{triangledown} ,{dagger}

Rafael C. Prados Rosales and Antonio Di Pietro*

Departamento de Genética, Universidad de Córdoba, 14071 Córdoba, Spain

Received 19 July 2007/ Accepted 9 November 2007

Vegetative hyphal fusion (VHF) is a ubiquitous phenomenon in filamentous fungi whose biological role is poorly understood. In Neurospora crassa, the mitogen-activated protein kinase (MAPK) Mak-2 and the WW domain protein So are required for efficient VHF. A MAPK orthologous to Mak-2, Fmk1, was previously shown to be essential for root penetration and pathogenicity of the vascular wilt fungus Fusarium oxysporum. Here we took a genetic approach to test two hypotheses, that (i) VHF and plant infection have signaling mechanisms in common and (ii) VHF is required for efficient plant infection. F. oxysporum mutants lacking either Fmk1 or Fso1, an orthologue of N. crassa So, were impaired in the fusion of vegetative hyphae and microconidial germ tubes. {Delta}fmk1 {Delta}fso1 double mutants exhibited a more severe fusion phenotype than either single mutant, indicating that the two components function in distinct pathways. Both {Delta}fso1 and {Delta}fmk1 strains were impaired in the formation of hyphal networks on the root surface, a process associated with extensive VHF. The {Delta}fso1 mutants exhibited slightly reduced virulence in tomato fruit infection assays but, in contrast to {Delta}fmk1 strains, were still able to perform functions associated with invasive growth, such as secretion of pectinolytic enzymes or penetration of cellophane sheets, and to infect tomato plants. Thus, although VHF per se is not essential for plant infection, both processes have some signaling components in common, suggesting an evolutionary relationship between the underlying cellular mechanisms.

* Corresponding author. Mailing address: Departamento de Genética, Universidad de Córdoba, Campus de Rabanales Edif. C5, 14071 Córdoba, Spain. Phone: (34) 957 218981. Fax: (34) 957 212072. E-mail: ge2dipia{at}uco.es

{triangledown} Published ahead of print on 26 November 2007.

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

Eukaryotic Cell, January 2008, p. 162-171, Vol. 7, No. 1
1535-9778/08/$08.00+0     doi:10.1128/EC.00258-07
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»