Growth and development of Stevia rebaudiana (Bertoni) through exogenous application of abscisic and jasmonic acid under cadmium stressmium Stress

Growth and development of stevia through acid under cadmium stres

Abstract

Cadmium (Cd) contamination poses a critical threat to crop productivity, physiology, and human health. Stevia rebaudiana, a commercially important medicinal and sweetener plant, is highly vulnerable to heavy metal stress, necessitating strategies to maintain growth and quality in contaminated soils. This study investigated the capacity of abscisic acid (ABA) and jasmonic acid (JA), applied individually and combined, to mitigate cadmium-induced morphological, physiological, and biochemical impairments in S. rebaudiana. Plants were exposed to graded Cd levels (0, 2, 4, 6, 8, 10 mg kg⁻¹ soil) and treated with 10 μM ABA, 50 μM JA, and their combination. The results indicated that Cadmium stress significantly reduced plant height, biomass, root growth, and photosynthetic pigments while increasing oxidative stress markers (MDA and H₂O₂) accumulation. Exogenous ABA and JA substantially alleviated these adverse effects, with the combined treatment (10 μM ABA + 50 μM JA) exhibiting the most pronounced improvement across all Cd concentrations. Plants treated with 10 μM ABA + 50 μM JA displayed enhanced growth recovery, photoprotection, water balance, and oxidative damage suppression, approaching control levels at moderate Cd stress. These findings demonstrate that combined application of ABA and JA more effectively fortified stevia against Cd toxicity by modulating growth, photosynthetic pigments, osmotic adjustment, and antioxidant capacity.

Ann. Bangladesh Agric. 30(1): 99-116