Book with abstracts from the COST Action 0905 meeting in ... - UMB

CONTROLLING CADMIUM ACCUMULATION IN PLANTS
Andrea Nesler, Giovanni Dal Corso, Antonella Furini
Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona
(Italy)
Keywords: CzcCBA transporter, heavy metals, phytoremediation, Pseudomonas
putida
This study is focalized on the expression in planta of the trans-envelope pump CzcCBA,
typical of gram-negative bacteria as Pseudomonas putida, selected in this study. The
complex is constituted of three components (CzcA, CzcB, CzcC) that arrange a
chemiosmotic antiporter, conferring heavy metal resistance. Since CzcCBA transports
heavy metals across the membrane, we investigated its application to modulate cadmium
accumulation in plants.
Constructs were created to (i) identify the localization of proteins in the plant cell and (ii)
to analyze their effect on shoot metal accumulation:
(i) CzcA, CzcB and CzcC were fused to eGFP. Protoplasts transfection highlighted
probable plasma-membrane and nuclear localization of CzcC. Results concerning CzcA
and CzcB need further investigation.
(ii) Arabidopsis thaliana and Nicotiana tabacum plants were stably transformed with the
information driving the overexpression of the three genes separately. Preliminary data in
tobacco, show that plants are phenotypically normal and that CzcA and CzcB alone are able
to lower shoot cadmium amounts in transgenic plants, when compared to wild type.
Considering that the Czc system is constituted of three subunits, transgenic plants
harboring the single Czc genes are being crossed, to isolate individuals that carry the
complete CzcCBA complex and to verify whether the entire transporter confer different
cadmium transport into plants.