title: The arbuscular mycorrhizal fungus Glomus mosseae gives contradictory effects on phosphorus and arsenic acquisition by Medicago sativa Linn.
abstract: Mycorrhizal fungi may play an important role in protecting plants against arsenic (As) contamination. However, little is known about the direct and indirect involvement of arbuscular mycorrhizal fungi (AMF) in detoxification mechanisms. A compartmented pot cultivation system ('cross-pots') is used here to investigate the roles of AMF Glomus mosseae in plant phosphorus (P) and As acquisition by Medicago sativa, and P-As interactions. The results indicate that fungal colonization dramatically increased plant dry weight by a factor of around 6, and also substantially increased both plant P and As contents (i.e. total uptake). Irrespective of P and As addition levels, AM plants had shoot and root P concentrations 2 fold higher, but As concentrations significantly lower, than corresponding uninoculated controls. The decreased shoot As concentrations were largely due to "dilution effects" that resulted from stimulated growth of AM plants and reduced As partitioning to shoots. The study provides further evidence for the protective effects of AMF on host plants against As contamination, and have uncovered key aspects of underlying mechanisms. The possible application of AMF in remediation practices is discussed.
authors.affiliation: Department of Soil Environmental Sciences/State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, P.R. China.
authors.forename: Baodong
authors.initials: B
authors.lastname: Chen
authors.forename: Xueyi
authors.initials: X
authors.lastname: Xiao
authors.forename: Yong-Guan
authors.initials: YG
authors.lastname: Zhu
authors.forename: F Andrew
authors.initials: FA
authors.lastname: Smith
authors.forename: Z Miao
authors.initials: ZM
authors.lastname: Xie
authors.forename: Sally E
authors.initials: SE
authors.lastname: Smith
mesh_terms: D001151:Arsenic / Q000378:metabolism*; D001673:Biodegradation, Environmental; D025301:Hyphae / Q000254:growth & development; D000455:Medicago sativa / Q000254:growth & development / Q000378:metabolism* / Q000382:microbiology*; D038821:Mycorrhizae / Q000502:physiology*; D010758:Phosphorus / Q000378:metabolism; D018517:Plant Roots / Q000254:growth & development / Q000378:metabolism / Q000382:microbiology; D018520:Plant Shoots / Q000254:growth & development / Q000378:metabolism; D012989:Soil Pollutants / Q000378:metabolism*
chemical_list: D012989:Soil Pollutants; D010758:Phosphorus; D001151:Arsenic