Assessing cadmium (Cd) and arsenic (As) bioaccumulation and physiological and biochemical responses of Tagetes erecta L.

Exposure to high levels of heavy metals has been reported to induce the generation of reactive oxygen species (ROS), which can affect various biochemical and physiological functions in plants. The present study examined the effects of two common heavy metals, cadmium (Cd) and arsenic (As), on the physiological and biochemical parameters of Tagetes erecta L. The study focused on the effects of these metals on proline and polyphenol content, shoot and root length, fresh weight, chlorophyll content, and antioxidant enzyme activities (APX, CAT and GR) in T. erecta. The results showed that Cd and As exposure reduced shoot length (59.667 and 57.747 cm), root length (6.1 and 5.425 cm), fresh weight of shoots (13.053 and 11.571 g), and fresh weight of roots (1.925 and 1.671 g). The highest accumulation of Cd and As was observed in root tissues (257.324 and 42.26 mg kg-¹, respectively). A decline in chlorophyll content along with increased levels of proline and polyphenols was also recorded. Tagetes erecta is easy to cultivate, exhibits tolerance to heavy metals, and due to its high biomass production, it has potential for the remediation of heavy metal–contaminated soils.