Plant metallothioneins are proteins thought to sequester excess amounts of certain metal ions . These low molecular weight proteins (4–8 kDa) were discovered in mature wheat embryos about 30 years ago . Metallothioneins represent Cys-rich metal chelators able to coordinate metals atoms (e.g. Zn, Cd and Cu ions) and found to play a role in cellular processes such as regulation of cell growth, proliferation and DNA damage repair. But how metallothioneins fulfill these cellular roles, is yet to be discovered [49, 50]. Expression of plant metallothionein genes has been observed in a variety of senescing tissues, such as leaves and stems, ripened fruits and wounded tissues . Recent reports show that MTs (metallothionein’s) are also involved in the scavenging of reactive oxygen species (ROS) .