Figure 1.

Effectiveness in cadmium phytoextraction of 3-wk old M. truncatula plants colonised by G. irregulare (CdGi) relative to those non-inoculated (Cd), as measured by shoot tolerance index (A), root-to-shoot transport factor (B), and metal partitioning in shoot and root tissues (C). The tolerance indices for shoots of mycorrhizal and non-mycorrhizal M. truncatula plants were calculated as the ratio of biomass (g fresh weight) for plants grown in Cd-spiked substrate to plants grown in Cd-free substrate. The contribution of shoots to plant biomass was measured as the ratio of shoot biomass (g fresh weight) to that of whole plant. Root-to-shoot translocation rates for Cd were calculated in mycorrhizal and non-mycorrhizal plants as the ratio of the Cd amount (μg) in shoots to that in root. Cd partitioning indices corresponded to the metal quantities (μg) mobilized in plant organs. For two independent biological experiments (Exp), histograms represent means of three replicates (means ± SD, n = 3). Means marked with different letters indicate significant difference at p < 0.05.