Compartmentation and complexation of metals in hyperaccumulator plants
Hyperaccumulators are being intensely investigated. They are not only interesting in scientific context due to their strange behaviour in terms of dealing with high concentrations of metals, but also because of their use in phytoremediation and phytomining, for which understanding the mechanisms of...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2013-09-01
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| Series: | Frontiers in Plant Science |
| Subjects: | |
| Online Access: | http://journal.frontiersin.org/Journal/10.3389/fpls.2013.00374/full |
| _version_ | 1818265352964931584 |
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| author | Barbara eLeitenmaier Hendrik eKüpper |
| author_facet | Barbara eLeitenmaier Hendrik eKüpper |
| author_sort | Barbara eLeitenmaier |
| collection | DOAJ |
| description | Hyperaccumulators are being intensely investigated. They are not only interesting in scientific context due to their strange behaviour in terms of dealing with high concentrations of metals, but also because of their use in phytoremediation and phytomining, for which understanding the mechanisms of hyperaccumulation is crucial. Hyperaccumulators naturally use metal accumulation as a defence against herbivores and pathogens, and therefore deal with accumulated metals in very specific ways of complexation and compartmentation, different from non-hyperaccumulator plants and also non-hyperaccumulated metals. For example, in contrast to non-hyperaccumulators, in hyperaccumulators even the classical phytochelatin-inducing metal, cadmium, is predominantly not bound by such sulfur ligands, but only by weak oxygen ligands. This applies to all hyperaccumulated metals investigated so far, as well as hyperaccumulation of the metalloid arsenic. Stronger ligands, as they have been shown to complex metals in non-hyperaccumulators, are in hyperaccumulators used for transient binding during transport to the storage sites. This confirmed that enhanced active metal transport, and not metal complexation, is the key mechanism of hyperaccumulation. Hyperaccumulators tolerate the high amount of accumulated heavy metals by sequestering them into vacuoles, usually in large storage cells of the epidermis. This is mediated by strongly elevated expression of specific transport proteins in various tissues from metal uptake in the shoots up to the storage sites in the leaf epidermis. However, this mechanism seems to be very metal specific. Non-hyperaccumulated metals in hyperaccumulators seem to be dealt with like in non-hyperaccumulator plants, i.e. detoxified by binding to strong ligands such as metallothioneins. |
| first_indexed | 2024-12-12T19:49:27Z |
| format | Article |
| id | doaj.art-6a5c1bdda72646289e847ea9faac8672 |
| institution | Directory Open Access Journal |
| issn | 1664-462X |
| language | English |
| last_indexed | 2024-12-12T19:49:27Z |
| publishDate | 2013-09-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Plant Science |
| spelling | doaj.art-6a5c1bdda72646289e847ea9faac86722022-12-22T00:14:01ZengFrontiers Media S.A.Frontiers in Plant Science1664-462X2013-09-01410.3389/fpls.2013.0037455114Compartmentation and complexation of metals in hyperaccumulator plantsBarbara eLeitenmaier0Hendrik eKüpper1Universität KonstanzUniversität KonstanzHyperaccumulators are being intensely investigated. They are not only interesting in scientific context due to their strange behaviour in terms of dealing with high concentrations of metals, but also because of their use in phytoremediation and phytomining, for which understanding the mechanisms of hyperaccumulation is crucial. Hyperaccumulators naturally use metal accumulation as a defence against herbivores and pathogens, and therefore deal with accumulated metals in very specific ways of complexation and compartmentation, different from non-hyperaccumulator plants and also non-hyperaccumulated metals. For example, in contrast to non-hyperaccumulators, in hyperaccumulators even the classical phytochelatin-inducing metal, cadmium, is predominantly not bound by such sulfur ligands, but only by weak oxygen ligands. This applies to all hyperaccumulated metals investigated so far, as well as hyperaccumulation of the metalloid arsenic. Stronger ligands, as they have been shown to complex metals in non-hyperaccumulators, are in hyperaccumulators used for transient binding during transport to the storage sites. This confirmed that enhanced active metal transport, and not metal complexation, is the key mechanism of hyperaccumulation. Hyperaccumulators tolerate the high amount of accumulated heavy metals by sequestering them into vacuoles, usually in large storage cells of the epidermis. This is mediated by strongly elevated expression of specific transport proteins in various tissues from metal uptake in the shoots up to the storage sites in the leaf epidermis. However, this mechanism seems to be very metal specific. Non-hyperaccumulated metals in hyperaccumulators seem to be dealt with like in non-hyperaccumulator plants, i.e. detoxified by binding to strong ligands such as metallothioneins.http://journal.frontiersin.org/Journal/10.3389/fpls.2013.00374/fullmetal transportOrganic acidsNicotianaminephytochelatinindicatorhyperaccumulator/hypertolerance |
| spellingShingle | Barbara eLeitenmaier Hendrik eKüpper Compartmentation and complexation of metals in hyperaccumulator plants Frontiers in Plant Science metal transport Organic acids Nicotianamine phytochelatin indicator hyperaccumulator/hypertolerance |
| title | Compartmentation and complexation of metals in hyperaccumulator plants |
| title_full | Compartmentation and complexation of metals in hyperaccumulator plants |
| title_fullStr | Compartmentation and complexation of metals in hyperaccumulator plants |
| title_full_unstemmed | Compartmentation and complexation of metals in hyperaccumulator plants |
| title_short | Compartmentation and complexation of metals in hyperaccumulator plants |
| title_sort | compartmentation and complexation of metals in hyperaccumulator plants |
| topic | metal transport Organic acids Nicotianamine phytochelatin indicator hyperaccumulator/hypertolerance |
| url | http://journal.frontiersin.org/Journal/10.3389/fpls.2013.00374/full |
| work_keys_str_mv | AT barbaraeleitenmaier compartmentationandcomplexationofmetalsinhyperaccumulatorplants AT hendrikekupper compartmentationandcomplexationofmetalsinhyperaccumulatorplants |