title: Cytochemical localization of calcium and X-ray microanalysis of Catharanthus roseus L. infected with phytoplasmas.
abstract: The potassium pyroantimonate (KPA) Ca(2+) precipitation technique, X-ray microanalysis and Electron Energy Loss Spectroscopy carried out by transmission electron microscopy were used to analyze the Ca(2+) distribution in Catharanthus roseus L. leaves infected with phytoplasmas belonging to different taxonomic groups, and in phytoplasma cells. The analysis revealed that the distribution of Ca(2+) was different in healthy and diseased plants (where the KPA deposits were numerous) and no differences were observed in the tissues of the three types of infected C. roseus L. Since no KPA precipitates were visible in the phloem and on phytoplasma cells, it is likely that Ca(2+) ions are not directly involved in phytoplasma replication, but, in infected cells is a response to the pathogen indicative of a higher Ca(2+) in the plasmalemma.
authors.affiliation: Dipartimento di Biologia Applicata alla Difesa delle Piante, Università di Udine, Via delle Scienze 208, Udine 33100, Italy. rita.musetti@pdef.uniud.it
authors.forename: Rita
authors.initials: R
authors.lastname: Musetti
authors.forename: Maria Augusta
authors.initials: MA
authors.lastname: Favali
mesh_terms: D000965:Antimony / Q000737:chemistry; D002118:Calcium / Q000378:metabolism*; D030008:Catharanthus / Q000378:metabolism / Q000382:microbiology* / Q000648:ultrastructure*; D011232:Chemical Precipitation; D004577:Electron Probe Microanalysis; D008854:Microscopy, Electron / Q000379:methods; D045582:Phytoplasma / Q000145:classification / Q000472:pathogenicity*; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves / Q000382:microbiology; D013057:Spectrum Analysis / Q000379:methods
chemical_list: C009002:potassium antimonate; D000965:Antimony; D002118:Calcium