For OrgHg in shoots of L. perenne, a significant and strong positive
relationship was obtained with the respective root concentrations
(r2 = 0.60; p b 0.01, log-transformed) indicating that the
OrgHg levels observed in the aboveground plant parts derive from
the translocation of OrgHg from the roots. This was also observed
in studies with rice (Meng et al., 2011). In fact, Qiu et al. (2008)
reported that OrgHg is more easily translocated to aboveground plant
parts than IHg. According to Krupp et al. (2009) the easier translocation
of OrgHg compared to IHg occurs because phytochelatins can sequester
Hg(II) but not MeHg and therefore there is no retention of the organic
forms of the metal in the roots as occurs for inorganic ones.
Since only five samples of B. Junceawere analyzed itwas not possible
to infer on possible patterns of uptake and/or translocation of IHg or
OrgHg for this plant. From Fig. 3 these seem to be relatively lower