Data/hora: 04/06/2024 03:12:11

Biblioteca(s): | Embrapa Milho e Sorgo.
Data corrente: | 20/01/2006
Data da última atualização: | 30/05/2018
Autoria: | KOCHIAN, L. V.; PENCE, N. S.; LETHAM, D. L. D.; PINEROS, M. A.; MAGALHAES, J. V.; HOEKENGA, O. A.; GARVIN, D. F.
Afiliação: | JURANDIR VIEIRA DE MAGALHAES, CNPMS.
Título: | Mechanisms of metal resistance in plants: aluminum and heavy metals.
Ano de publicação: | 2002
Fonte/Imprenta: | Plant and Soil, The Hague, v. 247, n.1 , p. 109-119, 2002.
Idioma: | Inglês
Conteúdo: | Plants have evolved sophisticated mechanisms to deal with toxic levels of metals in the soil. In this paper, an overview of recent progress with regards to understanding fundamental molecular and physiological mechanisms underlying plant resistance to both aluminium (Al) and heavy metals is presented. The discussion of plant Al resistance will focus on recent advances in our understanding of a mechanism based on Al exclusion from the root apex, which is facilitated by Al-activated exudation of organic acid anions. The consideration of heavy metal resistance will focus on research into a metal hyperaccumulating plant species, the Zn/Cd hyperaccumulator, Thlaspi caerulescens, as an example for plant heavy metal research. Based on the specific cases considered in this paper, it appears that quite different strategies are used for Al and heavy metal resistance. For Al, our current understanding of a resistance mechanism based on excluding soil-borne Al from the root apex is presented. For heavy metals, a totally different strategy based on extreme tolerance and metal hyperaccumulation is described for a hyperaccumulator plant species that has evolved on naturally metalliferous soils. The reason these two strategies are the focus of this paper is that, currently, they are the best understood mechanisms of metal resistance in terrestrial plants. However, it is likely that other mechanisms of Al and/or heavy metal resistance are also operating in certain plant species, and there may be common features shared for dealing with Al and heavy resistance. Future research may uncover a number of novel metal resistance mechanisms in plants. Certainly the complex genetics of Al resistance in some crop plant species, such as rice and maize, suggests that a number of presently unidentified mechanisms are part of an overall strategy of metal resistance in crop plants..
Palavras-Chave: | Aluminium resistance; Anion channel; Heavy metal transport; Metal hyperaccumulation; Organic acid exudation.
Thesaurus Nal: | gene expression.
Categoria do assunto: | --
Registro original: | Embrapa Milho e Sorgo (CNPMS)
Exemplares: | CNPMS - (18244-1) - UPC - AP - DD -  -  -  - DIS