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https://hdl.handle.net/2440/64524
Type: | Conference paper |
Title: | Interactions between rhizosphere microorganisms and plants governing iron and phosphorus availability |
Author: | Marschner, P. Crowley, D. Rengel, Z. |
Citation: | Proceedings 19th World Congress of Soil Science: Soil solutions for a changing world, Brisbane, Australia, 1-6 August, 2010 / R. J. Gilkes and N. Prakongkep (eds.): pp.52-55 |
Publisher: | CSIRO |
Publisher Place: | DVD |
Issue Date: | 2010 |
ISBN: | 9780646537832 |
Conference Name: | World Congress of Soil Science (19th : 2010 : Brisbane, Queensland) |
Statement of Responsibility: | Petra Marschner, David Crowley and Zed Rengel |
Abstract: | Because Fe availability is low in most aerobic soil, microorganisms and plants release low molecular-weight compounds (chelators) which increase Fe availability. Microorganisms appear to be far more competitive than plants: they can utilise Fe bound to plant-derived chelators and decompose them, whereas microbial chelators are poor Fe sources for plants. However, some plants, such as grasses, grow well in Fe-deficient soils, which may be explained by the spatially and temporarily concentrated release of phytosiderophores. Plants and microorganisms have developed a number of strategies to increase soil P availability. Microorganisms can increase plant P uptake by mobilising more P than they require and by stimulating root growth and mycorrhizal colonisation. However, microorganisms may also decrease P availability by (i) net P immobilisation in their biomass, (ii) decomposition of P-mobilising root exudates and (iii) decreasing root growth or mycorrhizal colonisation. Depending on the availability of carbon, the microbial biomass can influence Fe and P availability to plants by acting as either a source or a sink. We propose the following hypothesis: at high availability of carbon such as in the zone immediately behind the root tip, Fe and P immobilisation dominates, whereas in the mature root zones with decreased C availability, mineralisation is dominant. While net Fe and P immobilisation behind the root tip is likely to directly decrease plant uptake, net mineralisation along the mature root zones that have a low capacity for nutrient uptake may have a relatively small effect on plant uptake. |
Keywords: | Carbon availability competition microbial biomass mobilisation phytosiderophores siderophores |
Rights: | © 2010 19th World Congress of Soil Science, Soil Solutions for a Changing World 1 – 6 August 2010, Brisbane, Australia. |
Description (link): | http://trove.nla.gov.au/work/37679232 http://www.iuss.org/19th%20WCSS/19th%20WCSS_Handbook_REAL%20HANDBOOK_V10_BACK%20COVER%20change.pdf |
Published version: | http://www.iuss.org/19th%20WCSS/Author/Author_M.html |
Appears in Collections: | Agriculture, Food and Wine publications Aurora harvest |
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