Investigation on genes possibly involved in the response to heavy metals in Cynara cardunculus L

In plants, heavy metals stress may ultimately lead to serious consequences for human health. Cadmium (Cd) and arsenic (As) are frequently found in soils contaminated by mining or other industrial activities. Through food chain, these metals may enter into the human body, causing cardiovascular diseases and cancer. Cardoon (Cynara cardunculus L.) is a perennial crop, particularly adapted to the Mediterranean environment. It is able to accumulate heavy metals from polluted soils and thus it seems to tolerate this stress. The aim of this thesis was to characterize the transcriptional modulation of six genes that may be involved in the response to heavy metals stress and accumulation in C. cardunculus L.. The rate of seed germination of two different C. cardunculus varieties, altilis and sylvestris, was scored on agar plates medium containing Cd, As and Cd + As at 0, 10. 50, 100 and 200 µM concentrations. Transcriptional levels of Natural resistance of macrophage isoforms 1 (NRAMP1) and 3 (NRAMP3), Zinc/Iron Protein 11 (ZIP11), Heavy metal ATPase 3 (HMA3), Phosphate transporter 1 (PHT1) and ABC transporter C1 (ABCC1) were assayed by real time PCR in the two cardoon varieties, altilis and sylvestris, grown for two or three weeks on solid ½ MS medium containing Cd or As at 0, 25 and 50 µM concentrations. The results showed that both cardoon varieties were able to germinate under heavy metals contamination but just in sylvestris a clear correlation with an increased level of expression of genes involved in Cd and As transport was observed.