Effects of bisphenol A in soil on growth, photosynthesis activity, and genistein levels in crop plants (Vigna radiata)

Abstract

The compound bisphenol A (BPA), an endocrine-disrupting compound that can act as an estrogen, is widely used in the industrial manufacture of plastic products and epoxy resins. Because of the widespread use of the compound and its use in soil amendments, there is concern regarding its effects on crop plants, although comparatively little information is available on the ecotoxicity and potential risk of bisphenol. Here, we investigated the toxicity of BPA on mung bean (Vigna radiata) by evaluating growth, photosynthesis parameters, and phytoestrogen changes. Adverse effects on shoot growth were observed at a dose of 750 mg BPA/kg dry soil after acute (14 days) and chronic (21 days) exposure, and inhibition of root development was confirmed at a dose of 1000 mg BPA/kg dry soil. Chlorophyll content and stomatal size decreased at doses of 250 and 500 mg BPA/kg dry soil, respectively, and leaf spots due to leaf necrosis were observed in the groups that received 250 mg BPA/kg dry soil. Photosynthetic activity appeared to decrease in the groups that received the highest exposure, although it was not statistically significant. Meanwhile, exposure to bisphenol A increased the level of the phytoestrogen genistein. We propose that changes in genistein levels due to endocrine-disrupting compounds can be considered as a specific toxicity endpoint for endocrine-disrupting chemicals; further studies should explore this effect. This study confirmed the phytotoxicity of BPA at various endpoints and the results provide a basis for future ecological risk assessment for BPA.