Toxic effects of cadmium on the physiological and biochemical attributes of plants, and phytoremediation strategies: A review

• Published in: Environmental pollution (1987) 2023-05, Vol.325, p.121433-121433, Article 121433
• Main Authors: Li, Yanliang, Rahman, Shafeeq Ur, Qiu, Zhixin, Shahzad, Sher Muhammad, Nawaz, Muhammad Farrakh, Huang, Jianzhi, Naveed, Sadiq, Li, Lei, Wang, Xiaojie, Cheng, Hefa
• Format: Article
• Language: English
• Subjects: Biodegradation, Environmental; Cadmium - metabolism; Cd toxicity; Detoxification; Metals, Heavy - metabolism; Photosynthesis; Plant Roots - metabolism; Plants; Plants - metabolism; Reproductive parts; Soil Pollutants - metabolism; Tolerance; Vegetative parts
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2023.121433

Anthropogenic activities pose a more significant threat to the environment than natural phenomena by contaminating the environment with heavy metals. Cadmium (Cd), a highly poisonous heavy metal, has a protracted biological half-life and threatens food safety. Plant roots absorb Cd due to its high bioavailability through apoplastic and symplastic pathways and translocate it to shoots through the xylem with the help of transporters and then to the edible parts via the phloem. The uptake and accumulation of Cd in plants pose deleterious effects on plant physiological and biochemical processes, which alter the morphology of vegetative and reproductive parts. In vegetative parts, Cd stunts root and shoot growth, photosynthetic activities, stomatal conductance, and overall plant biomass. Plants’ male reproductive parts are more prone to Cd toxicity than female reproductive parts, ultimately affecting their grain/fruit production and survival. To alleviate/avoid/tolerate Cd toxicity, plants activate several defense mechanisms, including enzymatic and non-enzymatic antioxidants, Cd-tolerant gene up-regulations, and phytohormonal secretion. Additionally, plants tolerate Cd through chelating and sequestering as part of the intracellular defensive mechanism with the help of phytochelatins and metallothionein proteins, which help mitigate the harmful effects of Cd. The knowledge on the impact of Cd on plant vegetative and reproductive parts and the plants' physiological and biochemical responses can help selection of the most effective Cd-mitigating/avoiding/tolerating strategy to manage Cd toxicity in plants. [Display omitted] •Cd has high bioavailability to plants and is easily accumulated in their edible parts.•Cd exposure can adversely affect plants' physiological and biochemical attributes.•Cd poses detrimental effects on the morphology of vegetative and reproductive parts.•Plants activate several defense mechanisms to alleviate/avoid/tolerate Cd toxicity.•Phytoremediation strategies can be taken to minimize Cd toxicity and uptake in plants.