Associated mechanisms of aluminum tolerance in plants

Irineu Hartwig, Antônio Costa de Oliveira, Fernando Irajá Félix de Carvalho, Ivandro Bertan, José Antônio Gonzalez da Silva, Douglas André Mallmann Schmidt, Igor Pires Valério, Luciano Carlos Maia, Daniel Andrei Robe Fonseca, Cecília Estima Sacramento dos Reis

Abstract


Aluminum toxicity is one of the major limiting factor regarding plant development in acid soils. The use of liming for correcting soil pH is not viable for some of acid soil areas (technique or economic reasons), making the development of Al tolerant genotypes the best alternative. Thus, the tolerance mechanisms as well as the genetic basis of Al tolerance has deserved special attention in the scientific community. In the last years, a significant progress has been achieved towards these goals, as well as in developing cultivars adapted to acid soils. The Al tolerance mechanisms are divided basically in two classes: the exclusion mechanisms that act after absorption or blocking its entry in the root system and those involved in detoxification, complexing the Al in specific organelles, mainly in the vacuoles. In many species, physiological mechanisms have been reported as responsible for the activation of organic acids (mainly citrate and malate) that act as Al quelating agents, however many process are not yet understood and cleared. Currently, the basis for the internal detoxification is becoming clear through organic acid complexes and there sequestering by the vacuoles. Other potential mechanisms are the target for discussions.


Keywords


Al; acid soils; organic acids; exudates



DOI: http://dx.doi.org/10.5433/1679-0359.2007v28n2p219

Semina: Ciênc. Agrár.
Londrina - PR
E-ISSN 1679-0359
DOI: 10.5433/1679-0359
E-mail: semina.agrarias@uel.br
Este obra está licenciado com uma Licença Creative Commons Atribuição-NãoComercial 4.0 Internacional