title: The arbuscular mycorrhizal fungus Rhizophagus irregularis differentially regulates the copper response of two maize cultivars differing in copper tolerance.
abstract: Arbuscular mycorrhiza can increase plant tolerance to heavy metals. The effects of arbuscular mycorrhiza on plant metal tolerance vary depending on the fungal and plant species involved. Here, we report the effect of the arbuscular mycorrhizal fungus Rhizophagus irregularis on the physiological and biochemical responses to Cu of two maize genotypes differing in Cu tolerance, the Cu-sensitive cv. Orense and the Cu-tolerant cv. Oropesa. Development of the symbiosis confers an increased Cu tolerance to cv. Orense. Root and shoot Cu concentrations were lower in mycorrhizal than in non-mycorrhizal plants of both cultivars. Shoot lipid peroxidation increased with soil Cu content only in non-mycorrhizal plants of the Cu-sensitive cultivar. Root lipid peroxidation increased with soil Cu content, except in mycorrhizal plants grown at 250mg Cu kg-1soil. In shoots of mycorrhizal plants of both cultivars, superoxide dismutase, ascorbate peroxidase, catalase and glutathione reductase activities were not affected by soil Cu content. In Cu-supplemented soils, total phytochelatin content increased in shoots of mycorrhizal cv. Orense but decreased in cv. Oropesa. Overall, these data suggest that the increased Cu tolerance of mycorrhizal plants of cv. Orense could be due to an increased induction of shoot phytochelatin biosynthesis by the symbiosis in this cultivar.
authors.affiliation: Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, Profesor Albareda 1, 18008 Granada, Spain; Department of Chemistry and Biochemistry, Mendel University in Brno, Brno, Czech Republic.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Merlos
authors.affiliation: Department of Chemistry and Biochemistry, Mendel University in Brno, Brno, Czech Republic.
authors.forename: Ondrej
authors.initials: O
authors.lastname: Zitka
authors.affiliation: Department of Chemistry and Biochemistry, Mendel University in Brno, Brno, Czech Republic.
authors.forename: Adam
authors.initials: A
authors.lastname: Vojtech
authors.affiliation: Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, Profesor Albareda 1, 18008 Granada, Spain.
authors.forename: Concepción
authors.initials: C
authors.lastname: Azcón-Aguilar
authors.affiliation: Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, Profesor Albareda 1, 18008 Granada, Spain. Electronic address: nuria.ferrol@eez.csic.es.
authors.forename: Nuria
authors.initials: N
authors.lastname: Ferrol
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D003300:Copper / Q000378:metabolism*; D015227:Lipid Peroxidation; D038821:Mycorrhizae / Q000502:physiology*; D018384:Oxidative Stress; D054811:Phytochelatins / Q000378:metabolism; D003313:Zea mays / Q000254:growth & development / Q000378:metabolism / Q000382:microbiology*
chemical_list: D000975:Antioxidants; D003300:Copper; D054811:Phytochelatins
keywords: Arbuscular mycorrhiza; Copper; Maize; Oxidative stress; Phytochelatins