Cadmium Toxicity in Plants: Remedial Strategy Through Seed Priming

Abstract

Heavy metals (HMs) Hg > Cd> Pb> As> Ag> Ni > Co > Cu > Zn is the most popular environmental pollutants known since a long time ago as a major environmental threat; Cd is one of them. It has around 25-30 years of persistence in the environment, therefore, poses a hazardous impact on entire living things on the planet including plants, animals and human beings. Anthropogenic activities such as urban waste disposal, smelting, mining and the use of synthetic phosphate fertilizers are the major source of Cd in the soil. Plants grown in Cd-contaminated soil absorb the heavy metal through their roots and accumulate in different parts of the plant consequently limiting the entire phase of plant growth and development. It reduces the potential of water and nutrient uptake while it accelerates the production of reactive oxygen species (ROS) and oxidative damage to the cell membrane. Seed priming may be a dynamic approach to overcome phytotoxicity caused by the presence of cadmium more than the threshold level which is (3-5 mg g-1). Seed priming with various salts such (KNO3 , Mg (NO32) and Ca (NO32) and Growth hormones(Auxin, GA3 and Salicylic acid) participate in the betterment of seed germination, seedling establishment till the maturity of the crop by improving the defense system against the Cd toxicity.