Mechanisms of cadmium phytoremediation and detoxification in plants

As a consequence of industrial development, soil Cd pollution leads to crop contamination by Cd, posing a threat to food safety and human health. Excessive accumulation of Cd in plants also inhibits their growth via oxidative stress damage to their photosynthetic systems. Through evolutionary selection, plants have developed a set of efficient strategies to respond to Cd in their environments. These include the accumulation and detoxification of heavy metals. Cd is absorbed by plant roots through the apoplastic and symplastic pathways and then translocated to plant shoots via xylem loading, long-distance transport, and phloem redistribution. Simultaneously, plants initiate a series of mechanisms to reduce Cd toxicity,including cell wall adsorption, cytoplasmic chelation, and vacuolar sequestration. This review summarizes current knowledge of Cd accumulation and detoxification in plants.