Work

Exogenous gibberellic acid (GA₃) alleviates lead-induced phytotoxicity by modulating growth and antioxidant defence in spinach (Spinacia oleracea L.)

Year: 2026

Type: article

Abstract: Lead (Pb) contamination is a serious threat to vegetable production as it adversely affects plant growth, disrupts physiological and oxidative balance.To assess the effects of Pb stress (20 mg L-1) and the mitigating role of gibberellic acid (GA3; 100 mg L-1) on Spinacia oleracea L., a pot experiment was conducted, laid out in a completely randomized design (CRD) with 5 replications.A significant reduction was observed in plant height, root length, fresh weight and dry weight by 34.6%, 20.7%, 25.3%, and 25.2%, respectively under Pb exposure, compared with the control (p ≤ 0.05).Photosynthetic pigments also reduced with Pb stress, chlorophyll a (0.02 mg g⁻¹ FW), chlorophyll b (0.28 mg g⁻¹ FW), carotenoids (0.24 mg g⁻¹ FW) and relative water content (56.2%), resulting in disruption of photosynthetic activity.Importantly, GA₃ application to plants grown under Pb stress significantly alleviated Pb-induced oxidative damage by restoring growth traits.Application of GA₃ significantly increased chlorophyll content, carotenoids and relative water content.Pb stress triggered the antioxidant enzymatic activities, including superoxide dismutase, catalase, peroxidase, and ascorbate peroxidase, reflecting enhanced oxidative stress.GA₃ application under Pb stress further strengthened antioxidant defence, resulting in more efficient reactive oxygen species detoxification.

Source: Pakistan Journal of Botany

DOI: 10.30848/pjb2027-1(13)