title: Correlation between hormonal homeostasis and morphogenic responses in Arabidopsis thaliana seedlings growing in a Cd/Cu/Zn multi-pollution context.
abstract: To date, almost no information is available in roots and shoots of the model plant Arabidopsis thaliana about the hierarchic relationship between metal accumulation, phytohormone levels, and glutathione/phytochelatin content, and how this relation affects root development. For this purpose, specific concentrations of cadmium, copper and zinc, alone or in triple combination, were supplied for 12 days to in vitro growing seedlings. The accumulation of these metals was measured in roots and shoots, and a significant competition in metal uptake was observed. Microscopic analyses revealed that root morphology was affected by metal exposure, and that the levels of trans-zeatin riboside, dihydrozeatin riboside, indole-3-acetic acid and the auxin/cytokinin ratio varied accordingly. By contrast, under metal treatments, minor modifications in gibberellic acid and abscisic acid levels occurred. Real-time polymerase chain reaction analysis of some genes involved in auxin and cytokinin synthesis (e.g. AtNIT in roots and AtIPT in shoots) showed on average a metal up-regulated transcription. The production of thiol-peptides was induced by all the metals, alone or in combination, and the expression of the genes involved in thiol-peptide synthesis (AtGSH1, AtGSH2, AtPCS1 and AtPCS2) was not stimulated by the metals, suggesting a full post-transcriptional control. Results show that the Cd/Cu/Zn-induced changes in root morphology are caused by a hormonal unbalance, mainly governed by the auxin/cytokinin ratio.
authors.affiliation: School of Agricultural, Forestry, Food and Environmental Sciences, University of Basilicata, Viale dell'Ateneo Lucano, 10, I-85100, Potenza, Italy.
authors.forename: Adriano
authors.initials: A
authors.lastname: Sofo
authors.affiliation: School of Agricultural, Forestry, Food and Environmental Sciences, University of Basilicata, Viale dell'Ateneo Lucano, 10, I-85100, Potenza, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Vitti
authors.affiliation: School of Agricultural, Forestry, Food and Environmental Sciences, University of Basilicata, Viale dell'Ateneo Lucano, 10, I-85100, Potenza, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Nuzzaci
authors.affiliation: School of Agricultural, Forestry, Food and Environmental Sciences, University of Basilicata, Viale dell'Ateneo Lucano, 10, I-85100, Potenza, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Tataranni
authors.affiliation: School of Agricultural, Forestry, Food and Environmental Sciences, University of Basilicata, Viale dell'Ateneo Lucano, 10, I-85100, Potenza, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Scopa
authors.affiliation: Environmental Biology Centre for Environmental Sciences, Hasselt University, B-3590, Diepenbeek, Belgium.
authors.forename: Jaco
authors.initials: J
authors.lastname: Vangronsveld
authors.affiliation: Environmental Biology Centre for Environmental Sciences, Hasselt University, B-3590, Diepenbeek, Belgium.
authors.forename: Tony
authors.initials: T
authors.lastname: Remans
authors.affiliation: Department of Environmental Biology, "Sapienza" University of Rome, Piazzale A. Moro 5, I-00185, Rome, Italy.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Falasca
authors.affiliation: Department of Environmental Biology, "Sapienza" University of Rome, Piazzale A. Moro 5, I-00185, Rome, Italy.
authors.forename: Maria M
authors.initials: MM
authors.lastname: Altamura
authors.affiliation: Department of Life Sciences, University of Parma, Parco Area delle Scienze, I-43124, Parma, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Degola
authors.affiliation: Department of Life Sciences, University of Parma, Parco Area delle Scienze, I-43124, Parma, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Sanità di Toppi
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D002104:Cadmium / Q000633:toxicity; D003300:Copper / Q000633:toxicity; D003583:Cytokinins / Q000378:metabolism; D006706:Homeostasis; D007210:Indoleacetic Acids / Q000378:metabolism; D008670:Metals / Q000633:toxicity*; D054811:Phytochelatins / Q000378:metabolism; D010937:Plant Growth Regulators / Q000378:metabolism*; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D036226:Seedlings / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D015032:Zinc / Q000633:toxicity
chemical_list: D003583:Cytokinins; D007210:Indoleacetic Acids; D008670:Metals; D010937:Plant Growth Regulators; D002104:Cadmium; C030737:indoleacetic acid; D003300:Copper; D054811:Phytochelatins; D015032:Zinc