A versatile Lepidium sativum bioassay for use in ecotoxicological studies

Area of Science:

• Environmental toxicology
• Plant science
• Ecotoxicology

Background:

• Ecotoxicological analyses require reliable and efficient bioassays.
• Traditional methods can be time-consuming and resource-intensive.
• Garden cress (Lepidium sativum L.) offers potential as a model organism.

Purpose of the Study:

• To develop and validate a straightforward and efficient bioassay using garden cress.
• To assess the ecotoxicological effects of heavy metal compounds and sodium chloride on cress seedlings.
• To establish the relative toxicity of various heavy metals using the developed bioassay.

Main Methods:

• Garden cress seedlings were cultivated in hanging plastic bags on chromatography paper soaked with test substances.
• Digital scans were used to measure seedling length after the growth period.
• Germination rate, shoot and root length, total length, and root-to-shoot ratio were quantified for various heavy metal compounds and sodium chloride.

Main Results:

• The bioassay demonstrated sensitivity to different concentrations of heavy metal compounds and sodium chloride.
• Half maximal effective concentration (EC50) values were calculated for key growth parameters.
• Heavy metal toxicity order was determined as copper > cadmium > iron > lead > zinc > manganese based on effects on root length, total length, and root-to-shoot ratio.

Conclusions:

• The developed garden cress bioassay is a straightforward, efficient, and suitable method for ecotoxicological analyses.
• This bioassay can be effectively used for investigating water-soluble ecotoxicologically relevant substances.
• The study provides a clear ranking of heavy metal toxicity to garden cress.