Functional analysis of Triticum durum type 1 metallothionein gene (dMT) in response to varying levels of cadmium

The effect of varying levels of cadmium and correlated changes on the expression level of a type 1 metallothionein gene (dMT) were investigated in Triticum durum cv. Balcali-85. Increasing the cadmium concentration resulted in a decrease in the dry weights of roots and shoots, and the effect was stronger in roots. Roots also showed a higher capacity to accumulate cadmium. Southern blot analyses revealed that the dMT gene, delineated by two exons and a non-coding intron region, exists at a single locus in the T. durum genome. Changes in dMT gene expression during cadmium exposure were monitored by two approaches. Northern blot analyses showed that the transcript level in roots increased upon treatment with increasing cadmium, which was quantified by qRT-PCR as 4.5 fold of the base level at 10 μM Cd. These results show a positive correlation between cadmium exposure and expression of dMT gene in durum wheat, and will provide a basis for studies on the role of type 1 metallothioneins in cadmium response.