Determining the Impact of the AM-Mycorrhizosphere on “Dwarf” Sunflower Zn Uptake and Soil-Zn Bioavailability

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Title: Determining the Impact of the AM-Mycorrhizosphere on “Dwarf” Sunflower Zn Uptake and Soil-Zn Bioavailability
Authors: Audet, Patrick
Charest, Christiane
Date: 2010-11-26T21:25:20Z
Abstract: An in vivo compartmental pot greenhouse experiment involving “dwarf ” sunflower and an arbuscular mycorrhizal (AM) fungus was designed to assess the contribution of non-AM roots (rhizosphere), AM roots and extraradical hyphae (mycorrhizosphere), or strictly extraradical hyphae (hyphosphere) on plant growth, plant metal uptake, and soil parameters using the micronutrient zinc (Zn) as a typical metal contaminant.We observed that, at high soil-Zn concentrations, the mycorrhizosphere treatments had lower Zn concentrations (especially in shoots and flowers) and a lower incidence of leaf chlorosis than the rhizosphere treatments. These phytoprotective effects are believed to be related to AM-induced biosorption processes that reduce soil metal bioavailability to delay the onset of plant metal toxicity.We also observed that the presence of extraradical hyphae causes a slight alkalinisation of the proximal soil environment whereas roots tended to acidify it, this having significant consequences towardmetal bioavailability. Altogether, the AM symbiosis is considered to be a key component of ecosystem function involved in buffering plant growth conditions due to the processes of metal biosorption and hyphal alkalinisation which could contribute in enhancing the soil's resiliency.
URL: http://hdl.handle.net/10393/19675
DOI: 10.1155/2010/268540
CollectionBiologie // Biology
Libre accès uOttawa - Publications // uOttawa Open Access - Publications
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