2024-03-28T19:45:18Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/375052020-06-02T08:52:07Zcom_10261_75com_10261_6col_10261_328
2011-07-05T10:33:50Z
urn:hdl:10261/37505
Complexation of Hg with phytochelatins is important for plant Hg tolerance
Carrasco-Gil, Sandra
Álvarez-Fernández, Ana
Sobrino-Plata, Juan
Millán, Rocío
Carpena-Ruiz, Ramón O.
Leduc, Danika L.
Andrews, Joy C.
Abadía Bayona, Javier
Hernández, Luis E.
Biothiols
EXAFS
mass spectrometry
mercury
phytochelatins
soluble fraction
X-ray absorption spectroscopy
14 Pag., 3 Tabl., 5 Fig. The definitive version is available at: www3.interscience.wiley.com
Three-week-old alfalfa (Medicago sativa), barley (Hordeum vulgare) and maize (Zea mays) were exposed for 7 d to 30 µm of mercury (HgCl2) to characterize the Hg speciation in root, with no symptoms of being poisoned. The largest pool (99%) was associated with the particulate fraction, whereas the soluble fraction (SF) accounted for a minor proportion (<1%). Liquid chromatography coupled with electro-spray/time of flight mass spectrometry showed that Hg was bound to an array of phytochelatins (PCs) in root SF, which was particularly varied in alfalfa (eight ligands and five stoichiometries), a species that also accumulated homophytochelatins. Spatial localization of Hg in alfalfa roots by microprobe synchrotron X-ray fluorescence spectroscopy showed that most of the Hg co-localized with sulphur in the vascular cylinder. Extended X-ray Absorption Fine Structure (EXAFS) fingerprint fitting revealed that Hg was bound in vivo to organic-S compounds, i.e. biomolecules containing cysteine. Albeit a minor proportion of total Hg, Hg–PCs complexes in the SF might be important for tolerance to Hg, as was found with Arabidopsis thaliana mutants cad2-1 (with low glutathione content) and cad1-3 (unable to synthesize PCs) in comparison with wild type plants. Interestingly, high-performance liquid chromatography-electrospray ionization-time of flight analysis showed that none of these mutants accumulated Hg–biothiol complexes.
2011-07-05T10:33:50Z
2011-07-05T10:33:50Z
2011-05
artículo
Carrasco-Gil S, Álvarez-Fernández A, Sobrino-Plata J, Millán R, Carpena-Ruiz RO, Leduc DL, Andrews JC, Abadía J, Hernández LE. Complexation of Hg with phytochelatins is important for plant Hg tolerance. Plant Cell & Environment 34 (5): 778-791 (2011)
0140-7791
http://hdl.handle.net/10261/37505
10.1111/j.1365-3040.2011.02281.x
1365-3040
eng
http://dx.doi.org/10.1111/j.1365-3040.2011.02281.x
openAccess
John Wiley & Sons