title: Mycorrhiza and root hairs in barley enhance acquisition of phosphorus and uranium from phosphate rock but mycorrhiza decreases root to shoot uranium transfer.
abstract: Some phosphate rocks (PR) contain high concentrations of uranium (U), which are potentially toxic via accumulation in soils and food chains, and plant uptake of U is likely to be influenced by characteristics of roots and associated microorganisms. The relative importance of root hairs and mycorrhiza in U uptake from PR was studied using a root hairless barley (Hordeum vulgare) mutant (Brb) and its wild type (WT). Both plant genotypes were grown in pots with Glomus intraradices BEG 87, or in the absence of mycorrhiza, and three P treatments were included: nil P, 2% (w/w) PR and 50 mg KH(2)PO(4)-P kg(-1) soil. Mycorrhiza markedly increased d. wts and P contents of Brb amended with nil P or PR, but generally depressed d. wts of WT plants, irrespective of P amendments. Mycorrhiza had contrasting effects on U contents in roots and shoots, in particular in Brb where mycorrhiza increased root U concentrations but decreased U translocation from roots to shoots. The experiment supports our understanding of arbuscular mycorrhiza as being multifunctional by not only improving the utilization of PR by the host plant but also by contributing to the phytostabilization of uranium.
authors.affiliation: Department of Soil Environmental Science, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Baodong
authors.initials: B
authors.lastname: Chen
authors.forename: Per
authors.initials: P
authors.lastname: Roos
authors.forename: Ole K
authors.initials: OK
authors.lastname: Borggaard
authors.forename: Yong-Guan
authors.initials: YG
authors.lastname: Zhu
authors.forename: Iver
authors.initials: I
authors.lastname: Jakobsen
mesh_terms: D001467:Hordeum / Q000033:anatomy & histology / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology; D009154:Mutation; D038821:Mycorrhizae / Q000378:metabolism*; D010710:Phosphates; D010758:Phosphorus / Q000378:metabolism*; D018517:Plant Roots / Q000033:anatomy & histology / Q000235:genetics / Q000378:metabolism*; D018520:Plant Shoots / Q000378:metabolism; D014501:Uranium / Q000378:metabolism*
chemical_list: D010710:Phosphates; D010758:Phosphorus; D014501:Uranium