Prosopis juliXora is a tree species that grows
well in heavy metal laden industrial sites and accumulates
heavy metals. To understand the possible contribution of
metallothioneins (MTs) in heavy metal accumulation in
P. juliXora, we isolated and compared the metal binding
ability of three diVerent types of MTs (PjMT1-3). Glutathione
S-transferase fusions of PjMTs (GSTMT1-3) were
puriWed from Escherichia coli cells grown in the presence
of 0.3 mM cadmium, copper or zinc. Analysis of metal
bound fusion proteins using atomic absorption spectrometry
showed that PjMT1 bound higher levels of all three
heavy metals as compared to PjMT2 and PjMT3. A comparative
analysis of the genomic regions (including promoter
for all three PjMTs) is also presented. All three
PjMTs are induced by H2O2 and ABA applications. PjMT1
and PjMT2 are induced by copper and zinc respectively
while PjMT3 is induced by copper, zinc and cadmium. Variation
in induction of PjMTs in response to metal exposure
and their diVerential binding to metals suggests that each
MT has a speciWc role in P. juliXora. Of the three MTs analyzed,
PjMT1 shows maximum heavy metal sequestration
and is thus a potential candidate for use in heavy metal
phytoremediation.

http://link.springer.com/article/10.1007/s00438-008-0398-2