Exogenous application of citric acid alleviates copper-induced stress in Withania coagulans (Dunal)

The current study aimed to determine the mitigating effect of citric acid (CA) on various physiological and biochemical attributes in Withania coagulans, exposed to copper (Cu) stress. The viable seeds of Withania coagulans were planted in a controlled environment. After reaching the four-leaf stage, the plants were given simultaneous treatment with two concentrations of Cu [TCu1 and TCu2 (10mM, 15mM)] alone and/or with CA [TCa1 and TCa2 (05mM, 10mM)]. After harvesting, the physiological and biochemical characteristics of the plants were assessed. The findings demonstrated that using a higher dosage of Cu has significant toxic effects on plant growth and biomass. The agronomic attributes of the plant were significantly reduced by 24% (number of leaves), 22% (shoot length), 7% (root length), 8% (fresh weight), and 38% (dry weight) compared to the control. Higher concentration of Cu was also found toxic to photosynthetic pigments and significantly reduced by 27% (chl a), 6% (chl b), and 35% (carotenoids) compared to the control. However, the application of CA under Cu stress significantly improved the physiological attributes of Withania coagulans. The plant's agronomic traits significantly increased by 66% (number of leaves), 31% (shoot length), 87% (root length), 43% (fresh weight), and 78% (dry weight), whereas photosynthetic pigments by 25% (chl a), 58% (chl b), and 125% (carotenoids). Based on the results, it could be concluded that CA can play a role in mitigating the toxic effect of Cu in Withania coagulans