Authors: Nina A Lehr Aleksandra Adomas Frederick O Asiegbu Rüdiger Hampp Mika T Tarkka
Publish Date: 2009/10/02
Volume: 85, Issue: 2, Pages: 347-358
Abstract
The mycorrhization helper bacterium Streptomyces sp AcH 505 inhibits Norway spruce root infection and colonisation by the root and butt rot fungus Heterobasidion annosum 005 but not by the congeneric strain Heterobasidion abietinum 331 because of higher sensitivity of H annosum 005 towards the AcH 505derived naphthoquinone antibiotic WS5995 B Differences in antibiotic sensitivity between two isolates belonging to two species H annosum 005 and H abietinum 331 were investigated by comparative gene expression analysis using macroarrays and quantitative RTPCR after WS5995 B structurally related mollisin and unrelated cycloheximide application Treatment with 25 µM WS5995 B for 2 h resulted in a significant upregulation of expression of inosine5′monophosphate dehydrogenase phosphoglucomutase and GTPase genes while the expression of genes encoding for thioredoxin and glutathione dependent formaldehyde dehydrogenase was downregulated in the sensitive fungal strain No differential expression in the tolerant strain was detected Application of WS5995 B at higher concentrations over a time course experiment revealed that H annosum 005 and H abietinum 331 responded differently to WS5995 B The fungal gene expression levels depended on both the concentration of WS5995 B and the duration of its application The WS5995 Bunrelated cycloheximide caused highly specific changes in patterns of gene expression Our findings indicate considerable variations in response to bacterial metabolites by the isolates of the conifer pathogenWe are indebted to Margret Ecke for technical assistance in microbial cultures Dr Julia Riedlinger for WS5995 B preparation and Dr Karlheinz Seifert for providing purified mollisin We thank Dr Kari Korhonen and Dr Franz Oberwinkler for Heterobasidion isolates We further thank Åke Olson Magnus Karlsson and Jan Stenlid for making available plasmid clones in the present macroarray study This study was supported by the German Research Foundation DFG graduate college ‘Infection Biology’ NAL the Swedish Research Council for Agricultural Sciences and Forestry FORMAS the Carl Tryggers Stiftelse CTS Sweden and by Maj and Tor Nessling Foundation
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