Assessment of uptake and phytotoxicity of cyanobacterial extracts containing microcystins or cylindrospermopsin on parsley (Petroselinum crispum L.) and coriander (Coriandrum sativum L)

Blooms of harmful cyanobacteria that synthesize cyanotoxins are increasing worldwide. Agronomic plants can uptake these cyanotoxins and given that plants are ultimately ingested by humans, this represents a public health problem. In this research, parsley and coriander grown in soil and watered through 7 days with crude extracts containing microcystins (MCs) or cylindrospermopsin (CYN) in 0.1–1 μg mL⁻¹ concentration range were evaluated concerning their biomass, biochemical parameters and uptake of cyanotoxins. Although biomass, chlorophylls (a and b), carotenoids and glutathione-S-transferase of parsley and coriander exposed to the crude extracts containing MC or CYN had shown variations, these values were not statistically significantly different. Protein synthesis is not inhibited in coriander exposed to MC or CYN and in parsley exposed to MC. Also, glutathione reductase (GR) and glutathione peroxidase (GPx) in parsley and coriander was not affected by exposure to MC, and in coriander, the CYN did not induce statistically significant differences in these two antioxidative enzymes. Only parsley showed statistically significant increase in protein content exposed to 0.5 μg CYN mL⁻¹ (3.981 ± 0.099 mg g⁻¹ FW) compared to control (2.484 ± 0.145 mg g⁻¹ FW), statistically significant decrease in GR exposed to 0.1 μg CYN mL⁻¹ (0.684 ± 0.117 nmol min⁻¹ mg⁻¹ protein) compared to control (1.30 ± 0.06 nmol min⁻¹ mg⁻¹ protein) and statistically significant increase in GPx exposed to 1 μg CYN mL⁻¹ (0.054 ± 0.026 nmol min⁻¹ mg⁻¹ protein) compared to 0.5 μg CYN mL⁻¹ (0.003 ± 0.001 nmol min⁻¹ mg⁻¹ protein). These changes may be due to the induction of defensive mechanisms by plants by the presence of toxic compounds in the soil or probably to a low generation of reactive oxygen species. Furthermore, the parsley and coriander leaves and stems after 10 days of exposure did not accumulate microcystins or cylindrospermopsin.