title: Ca2+ and H+ ion fluxes near the surface of gravitropically stimulated Phycomyces sporangiophore.
abstract: The single-celled fungus Phycomyces blakesleeanus forms vertically oriented sporangiophores from hyphae, which display a negative gravitropic response. Longitudinal growth and gravitropic bending of these sporangiophores were measured with noninvasive H(+) and Ca(2+) ion-selective microelectrode measurements. The directions of H(+) and Ca(2+) fluxes, recorded at different locations of sporangiophores, were opposite when the sporangiophores were kept in vertical position. Ca(2+) fluxes were in most experiments positive (efflux), while H(+) fluxes were negative (influx). The direction of ion fluxes depended on developmental stage of sporangiophores and changed with gravistimulation.
authors.affiliation: Center for Multidisciplinary Studies, University of Belgrade, Serbia and Montenegro. vunduk@ibiss.bg.ac.yu
authors.forename: Branka
authors.initials: B
authors.lastname: Zivanović
mesh_terms: D002118:Calcium / Q000737:chemistry / Q000378:metabolism*; D002412:Cations; D002462:Cell Membrane / Q000378:metabolism; D018522:Gravitropism / Q000502:physiology*; D006859:Hydrogen / Q000737:chemistry / Q000378:metabolism*; D017736:Ion-Selective Electrodes; D008839:Microelectrodes; D010800:Phycomyces / Q000254:growth & development / Q000528:radiation effects*; D011522:Protons; D013172:Spores, Fungal / Q000254:growth & development
chemical_list: D002412:Cations; D011522:Protons; D006859:Hydrogen; D002118:Calcium