When exposed to 15 mg Cd kg−1, non-inoculated seedlings translocated
the metal into the shoots, reaching levels of 11.7 mg Cd kg−1
which are within the same order of magnitude as those obtained by
Kim et al., 2003 for P. sylvestris growing on 10 mg Cd kg−1 contaminated
forest soil. When Cd concentration in the soil increased from
15 to 30 mg Cd kg−1, a 2.2-fold increase of Cd concentration in the
root system was observed whereas no increase occurred in Cd concentration
in the shoots. These results suggest an ability of the plant
itself to accumulate the metal onto its root system, acting as an efficient
barrier to translocation onto the shoot, similarly to that reported
by other studies on heavy metal translocation (Arduini et al., 1996;
Bücking and Heyser, 1994; Disante et al., 2010).