Impact of Cd stress on cellular functioning and its amelioration by phytohormones: An overview on regulatory network

Among all non-essential heavy metals, cadmium (Cd) is perhaps the metal that has attracted the most attention in soil science and plant nutrition due to its potential toxicity to humans, and also its relative mobility in the soil-plant system. In plant system, Cd influences entire metabolism. It interferes with physiological activities of plants such as photosynthesis, gaseous exchange, nutrients absorption, and causes reduction in plant growth, dry matter accumulation and yield. It also results alteration in antioxidant production, cell cycle and division that leads to chromosomal aberrations and modification in gene expression. In order to cope with such situation plants have to develop several strategies. Among them phytohormones played an important role, but in presence of high level of Cd in the environment, plants are not able to carry out their normal functions. In such condition, exogenous application of phytohormones improves the plant metabolism. These phytohormones (plant growth regulators) act as active members of signal transduction cascade that involve in metal detoxification. Thus, this review describes mechanism behind application of phytohormones for metal remediation particularly Cd including its impact on morphological, biochemical and molecular characterization of the plants.