title: Calcium oxalate crystals in eucalypt ectomycorrhizae: morphochemical characterization.
abstract: Ectomycorrhizal fungi are ubiquitous in forest ecosystems, benefitting plants principally by increasing the uptake of water and nutrients such as calcium from the soil. Previous work has demonstrated accumulation of crystallites in eucalypt ectomycorrhizas, but detailed morphological and chemical characterization of these crystals has not been performed. In this work, cross sections of acetic acid-treated and cleared ectomycorrhizal fragments were visualized by polarized light microscopy to evaluate the location of crystals within cortical root cells. Ectomycorrhizal sections were also observed by scanning electron microscopy (SEM) coupled with energy dispersive x-ray (EDS) microprobe analysis. The predominant forms of crystals were crystal sand (granules) and concretions. Calcium, carbon and oxygen were detected by EDS as constituent elements and similar elemental profiles were observed between both crystal morphologies. All analyzed crystalline structures were characterized as calcium oxalate crystals. This is the first report of the stoichiometry and morphology of crystals occurring in eucalypt ectomycorrhizas in tropical soils. The data corroborates the role of ectomycorrhizae in the uptake and accumulation of calcium in the form of calcium oxalate crystals in hybrid eucalypt plants.
authors.affiliation: Departamento de Microbiologia, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil.
authors.forename: Victor Satler
authors.initials: VS
authors.lastname: Pylro
authors.forename: André Luiz Moreira
authors.initials: AL
authors.lastname: de Freitas
authors.forename: Wagner Campos
authors.initials: WC
authors.lastname: Otoni
authors.forename: Ivo Ribeiro
authors.initials: IR
authors.lastname: da Silva
authors.forename: Arnaldo Chaer
authors.initials: AC
authors.lastname: Borges
authors.forename: Maurício Dutra
authors.initials: MD
authors.lastname: Costa
mesh_terms: D002129:Calcium Oxalate / Q000737:chemistry*; D003460:Crystallization; D018360:Crystallography, X-Ray; D005052:Eucalyptus / Q000382:microbiology*; D008855:Microscopy, Electron, Scanning; D008859:Microscopy, Polarization; D038821:Mycorrhizae / Q000737:chemistry* / Q000378:metabolism
chemical_list: D002129:Calcium Oxalate