Acclimation of wheat to low-level cadmium or zinc generates its resistance to cadmium toxicity

The accumulation and elimination kinetics for Cd described by one-compartment model were determined in five subcellular fractions of wheat after exposure to 5.0 μM Cd with or without pre-exposure to 0.1 μM Cd or 5.0 μM Zn. The results show that the acclimation of wheat to Cd or Zn generates its resistance to Cd and decreased Cd accumulation in wheat. The acclimation of wheat to Cd or Zn enhanced the accumulation of Cd in the biological detoxified fractions especially the heat-stable fraction and decreased the accumulation of Cd in the metal sensitive fractions especially the heat-denatured proteins over time. Subsequently, the acclimation to Cd or Zn increased the activities of CAT and SOD in root and shoot to different extents compared to the unacclimated wheat. This study for the first time suggests that the acclimation of plant to low-level metal affects the accumulation and the toxicity of metal in plant.

► The acclimation of wheat to Cd or Zn decreased Cd accumulation in the wheat.
► Acclimation of wheat resulted in Cd transferring from sensitive fractions to detoxified ones over time.
► The activities of CAT and SOD were increased compared to the unacclimated wheat.