Cadmium toxicity in plants and alleviation through seed priming approach

Abstract

Heavy metals (Cd) contamination of soil and water due to anthropogenic activity, causing toxicity/stress, has potential to turn down the crop productivity and quality globally. Cd affects the fundamental and crucial processes of plants from seed germination to grain maturity, among them antioxidant defense and photosynthesis are prime one. Recent development in various disciplines of agricultural and biological sciences such as molecular breeding, integrative multiomics, and advance agronomical technology involved in heavy metal tolerance, although they are limited to lab conditions or less popular among farmers fields. Therefore, seed priming is promising and versatile approach to heavy metal stress tolerance. Seed priming with various organic and inorganic salts (CaCl2, Mg (NO3)2, proline), plant growth regulators (auxin, gibberellins, salicylic acid), showed the promising results in counteracts the effect of Cd. Seed priming involve in improvements of seed germination, seedling establishment, antioxidant defense, water and mineral nutrition, and carrying stress memory in progenies. To consider the above points, this review summarizes the effect of Cd toxicity on plant system and mineral nutrition. We also provide a glance of seed priming technology in respect to Cd stress tolerance at physiological, biochemical and molecular levels at different plant growth stages. © 2021, Indian Society for Plant Physiology.