Editor: Paolina Garbeva
Induction of trap formation in nematode-trapping fungi by a bacterium
Version of Record online: 25 JUL 2011
© 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved
FEMS Microbiology Letters
Volume 322, Issue 2, pages 157–165, September 2011
How to Cite
Li, L., Ma, M., Liu, Y., Zhou, J., Qu, Q., Lu, K., Fu, D. and Zhang, K. (2011), Induction of trap formation in nematode-trapping fungi by a bacterium. FEMS Microbiology Letters, 322: 157–165. doi: 10.1111/j.1574-6968.2011.02351.x
- Issue online: 11 AUG 2011
- Version of Record online: 25 JUL 2011
- Accepted manuscript online: 1 JUL 2011 10:27AM EST
- Received 26 January 2011; revised 29 May 2011; accepted 20 June 2011, Final version published online 25 July 2011.
- nematophagous fungi;
- soil bacteria;
- trap formation;
Three soil bacterial strains were identified as Chryseobacterium sp. TFB on the basis of their 16S rRNA gene sequences. Conidia of Arthrobotrys oligospora produced a few mycelial traps (MT) and conidial traps (CT) when cultured with bacterial cells that they did not produce when cultured with a bacterial cell-free culture filtrate. However, co-culture of A. oligospora with bacterial cells and bacteria-free filtrate simultaneously induced MT and CT in large amounts. With the increased concentration of bacteria-free filtrate, the number of typical CT increased, but conidial germination was progressively inhibited. Scanning electron microscopy of A. oligospora co-cultured with bacteria revealed that bacterial attachment to hyphae was a prerequisite to trap formation and that bacteria-free filtrate facilitated bacterial attachments to hyphae. The results that the addition of nutrients in co-culture medium decreased the number of traps suggest that this type of trap formation may be favoured at a low nutrient status. Eight fungi tested were able to form MT and CT when co-cultured with bacterial cells and bacteria-free culture filtrate, but the abilities varied among species. This study provides novel evidence that under laboratory conditions, soil bacteria attaching to hyphae could induce traps in nematode-trapping fungi.