title: Amelioration of iron toxicity: A mechanism for aluminum-induced growth stimulation in tea plants.
abstract: Tea plants (Camellia sinensis) are well adapted to acid soils with high Al availability. These plants not only accumulate high leaf Al concentrations, but also respond to Al with growth stimulation. Decreased oxidative stress has been associated with this effect. Why tea plants not exposed to Al suffer from oxidative stress has not been clarified. In this study, hydroponically grown tea plants treated with 0 to 300 μM Al were analyzed for growth, Al and Fe accumulation, and Al distribution by means of morin and hematoxylin staining. Roots of control plants stained black with hematoxylin. This indicates the formation of a Fe-hematoxylin complex. Young leaves of controls accumulated more than 1000 mg Fe kg(-1) dry weight. This concentration is above the Fe-toxicity threshold in most species. Supply of Al stimulated growth and reduced Fe uptake and transport. These results indicate that Al-induced growth stimulation might be due to alleviation of a latent Fe toxicity occurring in tea plants without Al supply.
authors.affiliation: Plant Science Department, University Tabriz, 51666 Tabriz, Iran.
authors.forename: Roghieh
authors.initials: R
authors.lastname: Hajiboland
authors.forename: Juan
authors.initials: J
authors.lastname: Barceló
authors.forename: Charlotte
authors.initials: C
authors.lastname: Poschenrieder
authors.forename: Roser
authors.initials: R
authors.lastname: Tolrà
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects; D000535:Aluminum / Q000378:metabolism* / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D028241:Camellia sinensis / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D018527:Hydroponics; D007501:Iron / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects; D018515:Plant Leaves / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism
chemical_list: D000535:Aluminum; D007501:Iron
keywords: Acid soil; Growth stimulation; Hematoxylin; Morin