Editor: Jim Prosser
Effects of selected root exudate components on soil bacterial communities
Article first published online: 13 JUL 2011
© 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved
FEMS Microbiology Ecology
Volume 77, Issue 3, pages 600–610, September 2011
How to Cite
Shi, S., Richardson, A. E., O'Callaghan, M., DeAngelis, K. M., Jones, E. E., Stewart, A., Firestone, M. K. and Condron, L. M. (2011), Effects of selected root exudate components on soil bacterial communities. FEMS Microbiology Ecology, 77: 600–610. doi: 10.1111/j.1574-6941.2011.01150.x
- Issue published online: 8 AUG 2011
- Article first published online: 13 JUL 2011
- Accepted manuscript online: 9 JUN 2011 10:27AM EST
- Received 9 September 2010; revised 22 May 2011; accepted 23 May 2011., Final version published online 13 July 2011.
- organic acids;
- Pinus radiata;
- root exudates
Low-molecular-weight organic compounds in root exudates play a key role in plant–microorganism interactions by influencing the structure and function of soil microbial communities. Model exudate solutions, based on organic acids (OAs) (quinic, lactic, maleic acids) and sugars (glucose, sucrose, fructose), previously identified in the rhizosphere of Pinus radiata, were applied to soil microcosms. Root exudate compound solutions stimulated soil dehydrogenase activity and the addition of OAs increased soil pH. The structure of active bacterial communities, based on reverse-transcribed 16S rRNA gene PCR, was assessed by denaturing gradient gel electrophoresis and PhyloChip microarrays. Bacterial taxon richness was greater in all treatments than that in control soil, with a wide range of taxa (88–1043) responding positively to exudate solutions and fewer (<24) responding negatively. OAs caused significantly greater increases than sugars in the detectable richness of the soil bacterial community and larger shifts of dominant taxa. The greater response of bacteria to OAs may be due to the higher amounts of added carbon, solubilization of soil organic matter or shifts in soil pH. Our results indicate that OAs play a significant role in shaping soil bacterial communities and this may therefore have a significant impact on plant growth.