MAS1, a 91aa protein confers Neurospora crassa sensitivity to a novel metabolite produced by a sponge-associated strain of Aspergillus tubingensis

Ref ID: 19325

Author:

Liat Koch, Anat Lodin, Micha Ilan, Shmuel Carmeli, Oded Yarden

Author address:

Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food
and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel

Full conference title:

Asian Mycological Congress 2013 and the 13th International Marine and Freshwater Mycology Symposium

Date: 19 August 2014

Abstract:

Sponge-associated fungi are a promising source of natural products, due to the unique
ecological niche in which they reside. We have isolated several Aspergillus spp. from the Mediterranean
marine sponge Psammocinia sp. One of them, an A. tubingensis strain, was found to secrete metabolites
that inhibit the growth of several fungi (Alternaria alternata, Rhizoctonia solani and Neurospora crassa).
At least two novel metabolites with antifungal activity were purified and their structures elucidated. The
compounds inhibited N. crassa growth (MIC=210μM) and affected hyphal morphology. Using random
tagged mutagenesis, we have identified N. crassa mutants exhibiting resistance to the compounds.
Plasmid rescue analysis indicated that a defect in a yet-uncharacterized gene (NCU03140.4), designated
mas-1, confers resistance to the compound. This was confirmed by analysis of the appropriate N. crassa
knock-out strain. Furthermore, complementation of the knockout strain restored sensitivity to the
compound. mas-1 expression indicates that the gene is highly expressed during conidial germination
when compared to young or mature hyphae. In addition, we analyzed the sensitivity of a 916;mas-1 strain to
several fungicides whose function results in impaired hyphal integrity. When grown in the presence of
either tebuconazole (an ergosterol biosynthesis inhibitor) or fludioxonil (an activator of the hyperosotic
stress response pathway), no significant difference between the 916;mas-1 strain and the wild type were
observed. Unexpectedly, the 916;mas-1 strain was only about half as sensitive to sublethal concentrations
of the chitin synthase inhibitor polyoxin D, suggesting alterations in the cell wall of 916;mas-1 may involve
changes in chitin deposition.

Abstract Number: I4-02

Conference Year: 2013

Link to conference website: NULL

New link: NULL

Conference abstracts, posters & presentations

Showing 10 posts of 17325 posts found.

  • Title

    Author

    Year

    Number

    Poster