Effects of exogenous gibberellic acid on growth and cadmium accumulation in Cyphomandra betacea seedlings

The contamination of orchards by the heavy metal cadmium (Cd) is a serious problem partly because of the toxicity of the Cd accumulated in fruits. Accordingly, developing suitable methods for minimizing the toxic effects of Cd on plants is necessary. In the current study, a pot-based experiment was conducted to assess the effects of various concentrations (0, 100, 200, 300, and 400 mg/L) of exogenous gibberellic acid (GA) on the growth and Cd accumulation in Cyphomandra betacea seedlings. The GA treatments promoted C. betacea seedling growth and increased the biomass as well as the chlorophyll, carotenoid, and soluble sugar contents. Additionally, the application of GA, especially the 300 mg/L solution, enhanced the net photosynthetic rate, stomatal conductance, the intercellular CO2 concentration, the transpiration rate, and the peroxidase, superoxide dismutase, and catalase activities. In contrast, the Cd content of C. betacea seedlings gradually decreased in response to increasing exogenous GA concentrations. Thus, the application of a GA solution improved C. betacea seedling growth and decreased the toxicity of Cd, with 300 mg/L representing the most effective GA concentration.

Automated summary

The application of exogenous gibberellic acid promoted the growth of Cyphomandra betacea seedlings and decreased the toxicity of cadmium, with 300 mg/L being the most effective concentration.