RESERVE MOBILIZATION DISORDER IN GERMINATING SEEDS OF VICIA FABA L. EXPOSED TO CADMIUM

The experiment was performed to study the germination of Vicia faba L. under the influence of cadmium (Cd) stress. Seeds were germinated for ten days by soaking in distilled water or cadmium nitrate solution. Germination rate, embryo radicle growth and water, Cd, and amino acid and sugar contents in cotyledons were investigated. Nutrient concentrations were also determined in the germination medium to quantify the solute leakage. Results showed that Cd-induced delay in seed germination can be associated to disturbance due to a failure in sugars and amino acids freeing. Such nutrients were lost in the imbibition medium at the expense of suitable mobilization to the growing embryonic axis. To explore the mechanism of cadmium toxicity, the solute leakage provides an indication of the way in which Cd might affect the germinative metabolism.