Production of fungal and bacterial growth modulating secondary metabolites is widespread among mycorrhiza-associated streptomycetes

• Published in: BMC microbiology Vol. 12; no. 1; p. 164
• Main Authors: Schrey, Silvia D, Erkenbrack, Eric, Früh, Elisabeth, Fengler, Svenja, Hommel, Kerstin, Horlacher, Nadine, Schulz, Dirk, Ecke, Margret, Kulik, Andreas, Fiedler, Hans-Peter, Hampp, Rüdiger, Tarkka, Mika T
• Format: Journal Article
• Language: English
• Published: London BioMed Central 02.08.2012; BioMed Central Ltd; BMC
• Subjects: Actinobacteria; Amanita muscaria; Anti-Bacterial Agents - metabolism; Antibiotics; Antifungal Agents - metabolism; Bacteria; Biological Microscopy; Biomedical and Life Sciences; Cluster Analysis; Colleges & universities; Disease resistance; DNA, Bacterial - chemistry; DNA, Bacterial - genetics; DNA, Ribosomal - chemistry; DNA, Ribosomal - genetics; Fungi; Fusarium oxysporum; Gene expression; Genetic aspects; Hebeloma cylindrosporum; Heterobasidion annosum; Immunization; Intercellular Signaling Peptides and Proteins - metabolism; Laccaria bicolor; Leaves; Life Sciences; Metabolites; Microbe-host interactions and microbial pathogenicity; Microbial Interactions; Microbiology; Molecular Sequence Data; Mycology; Mycorrhizae - drug effects; Mycorrhizae - growth & development; Mycorrhizas; Parasitology; Phylogeny; Physiological aspects; Picea - microbiology; Picea abies; Piloderma croceum; Pine trees; Plant diseases; Plant metabolites; Plant resistance; Research Article; RNA, Ribosomal, 16S - genetics; Secondary metabolites; Sequence Analysis, DNA; Streptomyces; Streptomyces - classification; Streptomyces - genetics; Streptomyces - isolation & purification; Streptomyces - metabolism; Streptomycetes; Surveys; Trees; Virology; Norway; Germany; Streptomyces; Cycloheximide; Amanita; Streptomyces Strain; Mycorrhiza Formation
• ISSN: 1471-2180; 1471-2180
• DOI: 10.1186/1471-2180-12-164

Background Studies on mycorrhiza associated bacteria suggest that bacterial-fungal interactions play important roles during mycorrhiza formation and affect plant health. We surveyed Streptomyces Actinobacteria, known as antibiotic producers and antagonists of fungi, from Norway spruce mycorrhizas with predominantly Piloderma species as the fungal partner. Results Fifteen Streptomyces isolates exhibited substantial variation in inhibition of tested mycorrhizal and plant pathogenic fungi ( Amanita muscaria, Fusarium oxysporum , Hebeloma cylindrosporum , Heterobasidion abietinum, Heterobasidion annosum , Laccaria bicolor, Piloderma croceum ). The growth of the mycorrhiza-forming fungus Laccaria bicolor was stimulated by some of the streptomycetes, and Piloderma croceum was only moderately affected. Bacteria responded to the streptomycetes differently than the fungi. For instance the strain Streptomyces sp. AcM11, which inhibited most tested fungi, was less inhibitory to bacteria than other tested streptomycetes. The determined patterns of Streptomyces -microbe interactions were associated with distinct patterns of secondary metabolite production. Notably, potentially novel metabolites were produced by strains that were less antagonistic to fungi. Most of the identified metabolites were antibiotics (e.g. cycloheximide, actiphenol) and siderophores (e.g. ferulic acid, desferroxiamines). Plant disease resistance was activated by a single streptomycete strain only. Conclusions Mycorrhiza associated streptomycetes appear to have an important role in inhibiting the growth of fungi and bacteria. Additionally, our study indicates that the Streptomyces strains, which are not general antagonists of fungi, may produce still un-described metabolites.