Genotoxicity Assessment in Plant Bioassays

Genotoxicity assessment in plant bioassays employs higher plants as sensitive indicators of DNA damage induced by chemical, physical or biological agents. The most widely used system is the Allium cepa root tip assay, in which meristematic cells are exposed to test substances and then analysed for changes in mitotic index, chromosomal aberrations and micronucleus formation. Complementary techniques such as the single-cell gel electrophoresis (Comet) assay provide quantitative measures of DNA strand breaks. These approaches reveal clastogenic (chromosome-breaking) and aneugenic (chromosome-number-altering) effects, enabling rapid screening of agrochemicals, environmental pollutants and nanomaterials. The simplicity, cost-effectiveness and high concordance with animal and human cell assays make plant bioassays indispensable for regulatory toxicology, environmental monitoring and risk assessment. Recent refinements include advanced imaging, molecular marker analysis and integration with oxidative stress biomarkers, providing mechanistic insight into genotoxin-induced cell cycle disruption and DNA repair dynamics. Such studies inform sustainable agriculture, ecological protection and human health safety on a global scale.

Research from Nature Portfolio

Recent studies have applied root tip assays to evaluate the genotoxic potential of commonly used pesticides and engineered nanomaterials. Investigations into malathion revealed a dose-dependent reduction in mitotic index, elevated lipid peroxidation and pronounced DNA damage in Allium cepa cells, linking oxidative stress to chromosomal aberrations. Foundational work on zinc oxide nanoparticles demonstrated that nanoparticle uptake leads to reactive oxygen species generation, mitochondrial dysfunction and a significant rise in chromosomal breaks and micronuclei. Research into copper oxide nanoparticles synthesised under varied pH conditions and surfactant assistance showed that smaller crystallite sizes intensify mitotic inhibition, chromosomal stickiness and spindle disturbances, emphasising the role of physicochemical properties in genotoxic risk. Collectively, these studies have refined assay protocols and underscored the importance of nanoparticle characterisation for accurate hazard evaluation.

Genotoxicity Assessment in Plant Bioassays publication trend

The graph below shows the total number of articles in genotoxicity assessment in plant bioassays across all publications each year (not limited to Nature Index journals).

Technical terms

Genotoxicity: The capacity of a substance to damage genetic material, causing mutations or chromosomal alterations.

Allium cepa root tip assay: A cytogenetic test using onion root meristem cells to detect mitotic disruptions and chromosomal damage.

Mitotic index: The percentage of cells undergoing mitosis, used to gauge cell division inhibition or stimulation.

Chromosomal aberration: Structural alteration of chromosomes, such as breaks, bridges or stickiness, indicative of clastogenic effects.

Micronucleus: A small, extranuclear body formed from lagging chromosome fragments or whole chromosomes, marking genotoxic events.

Comet assay: A single-cell electrophoresis technique that visualises DNA strand breaks as comet-like tails under fluorescence microscopy.

Aneugenic: Pertaining to agents that cause gain or loss of whole chromosomes by disrupting spindle function.

References

1. Assessment of malathion toxicity on cytophysiological activity, DNA damage and antioxidant enzymes in root of Allium cepa model. Scientific Reports (2020).
2. Mitochondrial and Chromosomal Damage Induced by Oxidative Stress in Zn2+ Ions, ZnO-Bulk and ZnO-NPs treated Allium cepa roots. Scientific Reports (2017).
3. CTAB Surfactant Assisted and High pH Nano-Formulations of CuO Nanoparticles Pose Greater Cytotoxic and Genotoxic Effects. Scientific Reports (2019).
4. Cyto-Genotoxic and Behavioral Effects of Flubendiamide in Allium cepa Root Cells, Drosophila melanogaster and Molecular Docking Studies. International Journal of Molecular Sciences (2023).
5. Evaluation of Clastogenic and Aneugenic Action of Two Bio-Insecticides Using Allium Bioassay. Journal of Xenobiotics (2025).
6. Allium cepa Bio Assay to Assess the Water and Sediment Cytogenotoxicity in a Tropical Stream Subjected to Multiple Point and Nonpoint Source Pollutants. Journal of Toxicology (2019).