Authors: Akitomo Kawasaki Erika R Watson Michael A Kertesz
Publish Date: 2011/12/30
Volume: 358, Issue: 1-2, Pages: 169-182
Abstract
Biodegradation of polycyclic aromatic hydrocarbons PAHs is accelerated in the presence of plants due to the stimulation of rhizosphere microbes by plant exudates nonspecific enhancement However plants may also recruit specific microbial groups in response to PAH stress specific enhancement In this study plant effects on the development of rhizosphere microbial communities in heterogeneously contaminated soils were assessed for three grasses ryegrass red fescue and Yorkshire fog and four legumes white clover chickpea subterranean clover and red lentilPlants were cultivated using a splitroot model with their roots divided between two independent pots containing either uncontaminated soil or PAHcontaminated soil pyrene or phenanthrene Microbial community development in the two halves of the rhizosphere was assessed by TRFLP bacterial and fungal community or DGGE bacterial community and by 16S rRNA gene tagpyrosequencingIn legume rhizospheres the microbial community structure in the uncontaminated part of the splitroot model was significantly influenced by the presence of PAHcontamination in the other part of the root system indirect effect but this effect was not seen for grasses In the contaminated rhizospheres Verrucomicrobia and Actinobacteria showed increased populations and there was a dramatic increase in Denitratisoma numbers suggesting that this genus may be important in rhizoremediation processesThis work was supported by the Heiwa Nakajima Foundation the University of Manchester Faculty of Life Sciences and the University of Sydney Faculty of Agriculture Food and Natural Resources We thank B Singh for assistance with soil characterization data
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