Due to increased global concern over the deleterious effects of toxic heavy metals in the environment, it has become necessary to develop plant genotypes that limit the uptake of heavy metals to aerial edible parts. To address this concern, we performed a glasshouse experiment to assess variations within tomato germplasm for cadmium (Cd) tolerance under control conditions and under simulated stress conditions. Significant differences (P
Metallothioneins (MTs) are ubiquitous metal-binding, cysteine-rich proteins, associated with metal accumulation and thus providing protection against toxic heavy metals such as cadmium (Cd). To investigate the mechanisms of enrichment of Cd in the earthworm Pheretima aspergillum, we isolated and cloned metallothionein-2 (MT-2) cDNA (538 bp) from P. aspergillum, analyzed its sequence, and examined MT-2 transcription levels by relative quantitative real-time PCR under different concentrations of Cd. The sequence of P.