title: Changes on organic acid secretion and accumulation in Plantago almogravensis Franco and Plantago algarbiensis Samp. under aluminum stress.
abstract: We investigated the effect of Al (400μM) on organic acids secretion, accumulation and metabolism in Plantago almogravensis Franco and Plantago algarbiensis Samp. Al induced a significant reduction on root elongation only in P. algarbiensis. Both species accumulated considerable amounts of Al (>120μgg(-1)) in their tissues, roots exhibiting the highest contents (>900μgg(-1)). Al stimulated malonic acid secretion in P. algarbiensis, while citric, succinic and malic acids were secreted by P. almogravensis. Moreover, Al uptake was accompanied by substantial increases of citric, oxalic, malonic and fumaric acids contents in the plantlets of either species. Overall, the acid metabolizing enzymes were not directly involved in the Al induced organic acid secretion and accumulation. Our data suggest that Al detoxification in P. almogravensis implies both secretion of organic acids from roots and tolerance to high Al tissue concentrations, while in P. algarbiensis only the tolerance mechanism seems to be involved.
authors.affiliation: Institute for Biotechnology and Bioengineering, Centre of Genomics and Biotechnology (IBB/CGB), Faculty of Sciences and Technology, University of Algarve, Campus de Gambelas, Ed. 8, 8005-139 Faro, Portugal.
authors.forename: Neusa
authors.initials: N
authors.lastname: Martins
authors.forename: Sandra
authors.initials: S
authors.lastname: Gonçalves
authors.forename: Paula B
authors.initials: PB
authors.lastname: Andrade
authors.forename: Patrícia
authors.initials: P
authors.lastname: Valentão
authors.forename: Anabela
authors.initials: A
authors.lastname: Romano
mesh_terms: D000222:Adaptation, Physiological; D000535:Aluminum / Q000493:pharmacokinetics* / Q000633:toxicity*; D001692:Biological Transport; D002264:Carboxylic Acids / Q000378:metabolism*; D019343:Citric Acid / Q000378:metabolism; D005650:Fumarates / Q000378:metabolism; D008658:Inactivation, Metabolic; D008293:Malates / Q000378:metabolism; D008314:Malonates / Q000378:metabolism; D019815:Oxalic Acid / Q000378:metabolism; D010937:Plant Growth Regulators / Q000378:metabolism*; D018517:Plant Roots / Q000254:growth & development / Q000378:metabolism*; D010943:Plantago / Q000254:growth & development / Q000378:metabolism*; D013312:Stress, Physiological; D019802:Succinic Acid / Q000378:metabolism
chemical_list: D002264:Carboxylic Acids; D005650:Fumarates; D008293:Malates; D008314:Malonates; D010937:Plant Growth Regulators; D019343:Citric Acid; C030298:malic acid; C032005:fumaric acid; D019815:Oxalic Acid; C030290:malonic acid; D019802:Succinic Acid; D000535:Aluminum