Poster: Phytoremediation
Abs #
982: Identification of molecular mechanisms involved in Cadmium tolerance and hyperaccumulation in THLASPI CAERULESCENS.
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Presenter: |
Nancy, Roosens H, nroosens@ulb.ac.be |
Authors | Nancy, Roosens H (A) Catherine, Bernard (A) Pierre, Meerts (B) Andrew, Smith (C) Nathalie, Verbruggen (A) | | Affiliations: |
(A): Lab de Physiologie et de Génétique Moléculaire des Plantes, Free University Brussels
(B): Lab de Génétique et Ecologie Végétale, Free University Brussels
(C): Department of Plant Sciences,University of Oxford
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Cd-hyperaccumulating plants have received much interest because of their potential for phytoremediation of soils contaminated with heavy metals. However, hyperaccumulator species have low biomass, severely constraining their applications in phytoremediation. Biotechnological tools have an enormous potential to contribute to the power of phytoremediation by transferring genes responsible for the hyperacummulator phenotype to plants with higher biomass. The major problem is the identification of the relevant genes for the hyperaccumulator phenotype and the limited understanding of the basic mechanisms underlying hyperaccumulation. The unique physiology of hyperaccumulators makes them ideal model systems to study the fundamental mechanisms that plants employ to tolerate and accumulate heavy metals.
In this study, we have characterized 7 populations of T. caerulescens from Western Europe. The populations differed considerably in their degree of metal hyperaccumulation and tolerance in hydroponic culture. Specifically, 2 populations (Ganges–France) were distinct in showing high degrees of both Cd tolerance and hyperaccumulation, whereas across the other populations there was a negative correlation between these 2 characters. Metal hyperaccumulation was negatively correlated with shoot: root biomass ratio, which, to a first approximation, could quantitatively account for the differences between populations in shoot Zn (but not Cd) concentrations. Measurements of Ca, Fe and Zn levels upon high Cd treatment support the proposal that Cd is taken up predominantly via a high-affinity uptake system for Fe in the Ganges populations, but via a lower-affinity pathway for Ca in other populations. Expression studies of genes involved in chelation and metal transport are in progress.
