Effect of gibberellic acid (GA₃) addition on physiological parameters and metal uptake in Phaseolus vulgaris seedlings under cadmium and lead stress

Abstract

Cadmium (Cd) and lead (Pb) are considered phytotoxic metals. Gibberellins (GAs) are a large group of tetracyclic diterpenoid phytohormones from GA₁ to GA₁₃₆. Common bean (Phaseolus vulgaris) is a legume that is very popular around the world. In this study, 50 µM gibberellic acid (GA₃) was added to bean seedlings treated with Cd plus Pb each at 100 or 200 mM concentration. Total chlorophyll content decreased by 25% and 40% in shoots of plant treated with 100 and 200 mM concentration, respectively compared to the control group. Based on results of the lipid peroxidation assay, in shoots, addition of GA₃ in the presence of 100 mM and 200 mM metal concentrations was also reduced by 48% and 32%, respectively. Antioxidant and nitric oxide (NO) scavenging activities (%) increased with the addition of GA₃. With the addition of GA₃ to 100 mM toxicity in shoots, 2,2-diphenyl-1-picrylhydrazyl (DPPH) activity increased by 17%. NO scavenging activity (%) was reduced by 27% and 53% in the presence of 100 mM and 200 mM concentrations of the two heavy metals (HMs), respectively, in the shoot compared to the control group. NO scavenging activity reduction of 40% in 100 mM stress and 60% in 200 mM stress were determined.

Graphical Abstract

Keywords:

• Antioxidant activity
• energy dispersive X-ray spectroscopy
• gibberellic acid
• heavy metals
• Phaseolus vulgaris
• scanning electron microscope

Acknowledgement

The author would like to thank Manisa Celal Bayar University (Turkey), Applied Science and Research Center (DEFAM) for their support in this study.

Disclosure statement

No potential conflict of interest was reported by the authors.