Mitigating cadmium toxicity in Strobilanthes alternata: Influence of 6-benzylaminopurine in modulating physiological responses and elemental constitution.

Heavy metal contamination of the environment is increasing alarmingly due to increased anthropogenic activities. Among the various heavy metals, cadmium is a highly toxic heavy metal requiring urgent removal from soil. Strobilanthes alternata, a herbaceous terrestrial plant, has been reported to be an excellent plant for Cd phytostabilization. The present study investigated the effect of 25 ppm of 6-Benzylaminopurine (6-BAP) foliar sprays on the modulation of the physiological responses and elemental constitution in S. alternata grown in 250 mg/kg CdCl2 treated soil. The administration of 6-BAP effectively relieved the toxic effects of Cd by enhancing the total soluble sugar and alkaloid content of leaves by 56 and 250%, respectively, the total soluble protein content of roots by 27%, the phenolic content of roots and leaves by 9 and 10% respectively, and flavonoid content of roots and leaves by 53 and 6% respectively, in Cd-stressed S. alternata. Moreover, the 6-BAP-induced elevation of the thiol content of roots indicated amplified sequestration of Cd, thereby inflicting less damage to the aboveground portions of Cd + 6-BAP-treated plants. This inference was confirmed by SEM-EDX analysis, which revealed high Cd weight percentages in the roots of Cd + 6-BAP-treated plants. The ionomics and CHNS analysis confirmed that 6-BAP ascribable alterations in the elemental content and distribution helped the plant tolerate the adverse effects of Cd in S. alternata. Thus, the 6-BAP treatment could be used as a suitable and ecologically acceptable amendment to reduce Cd-induced damage and enhance the Cd phytostabilization potential in S. alternata. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-025-01574-6.