POLYAMINES: ROLE IN ATTENUATION OF HEAVY METAL TOXICITY

Environmental changes resulted in a variety of stresses in plants of which heavy metal stress holds important position, affect the growth and development and trigger a series of morphological, physiological, biochemical and molecular changes in plants. When exposed heavy metal stress, the complex dynamickinetics of polyamine biosynthesis was observed. Polyamines are small organic polycations present in all organisms and have a leading role in signaling, plant growth and development and deliver tolerance to a cultivar against stresses. High accumulation of polyamines (putrescine, spermidine and spermine) in plantsduring heavy metal stress has been well reported and is correlated with increased tolerance to different plants under stressed condition. Genetic engineering of polyamine biosynthetic genes in crop plants is the way to create resistance heavy metal toxicity.