Production of plant growth modulating volatiles is widespread among rhizosphere bacteria and strongly depends on culture conditions
Article first published online: 20 SEP 2011
© 2011 Society for Applied Microbiology and Blackwell Publishing Ltd
Volume 13, Issue 11, pages 3047–3058, November 2011
How to Cite
Blom, D., Fabbri, C., Connor, E. C., Schiestl, F. P., Klauser, D. R., Boller, T., Eberl, L. and Weisskopf, L. (2011), Production of plant growth modulating volatiles is widespread among rhizosphere bacteria and strongly depends on culture conditions. Environmental Microbiology, 13: 3047–3058. doi: 10.1111/j.1462-2920.2011.02582.x
- Issue published online: 31 OCT 2011
- Article first published online: 20 SEP 2011
- Received 20 June, 2011; accepted 4 August, 2011.
Recent studies have suggested that bacterial volatiles play an important role in bacterial–plant interactions. However, few reports of bacterial species that produce plant growth modulating volatiles have been published, raising the question whether this is just an anecdotal phenomenon. To address this question, we performed a large screen of strains originating from the soil for volatile-mediated effects on Arabidopsis thaliana. All of the 42 strains tested showed significant volatile-mediated plant growth modulation, with effects ranging from plant death to a sixfold increase in plant biomass. The effects of bacterial volatiles were highly dependent on the cultivation medium and the inoculum quantity. GC-MS analysis of the tested strains revealed over 130 bacterial volatile compounds. Indole, 1-hexanol and pentadecane were selected for further studies because they appeared to promote plant growth. None of these compounds triggered a typical defence response, using production of ethylene and of reactive oxygen species (ROS) as read-outs. However, when plants were challenged with the flg-22 epitope of bacterial flagellin, a prototypical elicitor of defence responses, additional exposure to the volatiles reduced the flg-22-induced production of ethylene and ROS in a dose-dependent manner, suggesting that bacterial volatiles may act as effectors to inhibit the plant's defence response.