Melkamu Hinsermu,
Heavy metals and Al toxicity issues in plants and soils are a significant problem throughout the world. The most common heavy metal contaminants are Cadmium, Chromium, lead; Arsenic and Mercury do not have any beneficial effect on organisms, plant and environment. Heavy metals affect the plant both directly and indirectly. Adaptation mechanism of heavy metals and Al toxicity to plants are exclusion from the root apex and mechanisms that confer the ability to tolerate Al in the plant symplasm. Apoplast mechanisms are release of phenol compounds, mucilage formation, and genetic mechanisms of tolerance. Heavy metals and Al3+ are extremely problem on crop production. Therefore, intensive research will conducted in order to ascertain the mechanisms inherent to the heavy metals and Al toxicity and tolerance through selection and breeding process strategies to develop heavy metal and Al tolerant plants.